drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu: Mark local functions invoked by reference as static

Fixes the following W=1 kernel build warning(s):

 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:538:6: warning: no previous prototype for ‘pp_rv_set_wm_ranges’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:590:6: warning: no previous prototype for ‘pp_rv_set_pme_wa_enable’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:601:6: warning: no previous prototype for ‘pp_rv_set_active_display_count’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:614:6: warning: no previous prototype for ‘pp_rv_set_min_deep_sleep_dcfclk’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:627:6: warning: no previous prototype for ‘pp_rv_set_hard_min_dcefclk_by_freq’ [-Wmissing-prototypes]
 drivers/gpu/drm/amd/amdgpu/../display/amdgpu_dm/amdgpu_dm_pp_smu.c:640:6: warning: no previous prototype for ‘pp_rv_set_hard_min_fclk_by_freq’ [-Wmissing-prototypes]

Cc: Harry Wentland <harry.wentland@amd.com>
Cc: Leo Li <sunpeng.li@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm_pp_smu.c

@@ -535,7 +535,7 @@ bool dm_pp_get_static_clocks(
 	return true;
 }
 
-void pp_rv_set_wm_ranges(struct pp_smu *pp,
+static void pp_rv_set_wm_ranges(struct pp_smu *pp,
 		struct pp_smu_wm_range_sets *ranges)
 {
 	const struct dc_context *ctx = pp->dm;
@@ -587,7 +587,7 @@ void pp_rv_set_wm_ranges(struct pp_smu *pp,
 							   &wm_with_clock_ranges);
 }
 
-void pp_rv_set_pme_wa_enable(struct pp_smu *pp)
+static void pp_rv_set_pme_wa_enable(struct pp_smu *pp)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;
@@ -598,7 +598,7 @@ void pp_rv_set_pme_wa_enable(struct pp_smu *pp)
 		pp_funcs->notify_smu_enable_pwe(pp_handle);
 }
 
-void pp_rv_set_active_display_count(struct pp_smu *pp, int count)
+static void pp_rv_set_active_display_count(struct pp_smu *pp, int count)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;
@@ -611,7 +611,7 @@ void pp_rv_set_active_display_count(struct pp_smu *pp, int count)
 	pp_funcs->set_active_display_count(pp_handle, count);
 }
 
-void pp_rv_set_min_deep_sleep_dcfclk(struct pp_smu *pp, int clock)
+static void pp_rv_set_min_deep_sleep_dcfclk(struct pp_smu *pp, int clock)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;
@@ -624,7 +624,7 @@ void pp_rv_set_min_deep_sleep_dcfclk(struct pp_smu *pp, int clock)
 	pp_funcs->set_min_deep_sleep_dcefclk(pp_handle, clock);
 }
 
-void pp_rv_set_hard_min_dcefclk_by_freq(struct pp_smu *pp, int clock)
+static void pp_rv_set_hard_min_dcefclk_by_freq(struct pp_smu *pp, int clock)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;
@@ -637,7 +637,7 @@ void pp_rv_set_hard_min_dcefclk_by_freq(struct pp_smu *pp, int clock)
 	pp_funcs->set_hard_min_dcefclk_by_freq(pp_handle, clock);
 }
 
-void pp_rv_set_hard_min_fclk_by_freq(struct pp_smu *pp, int mhz)
+static void pp_rv_set_hard_min_fclk_by_freq(struct pp_smu *pp, int mhz)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;
@@ -661,7 +661,7 @@ static enum pp_smu_status pp_nv_set_wm_ranges(struct pp_smu *pp,
 	return PP_SMU_RESULT_OK;
 }
 
-enum pp_smu_status pp_nv_set_pme_wa_enable(struct pp_smu *pp)
+static enum pp_smu_status pp_nv_set_pme_wa_enable(struct pp_smu *pp)
 {
 	const struct dc_context *ctx = pp->dm;
 	struct amdgpu_device *adev = ctx->driver_context;