drm/amdgpu/pm: mark pcie link/speed arrays as const

They are read only.
Noticed-by: Dave Airlie <airlied@linux.ie>
Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/pm/inc/smu_v11_0.h

@@ -61,8 +61,8 @@
 #define LINK_WIDTH_MAX			6
 #define LINK_SPEED_MAX			3
 
-static __maybe_unused uint16_t link_width[] = {0, 1, 2, 4, 8, 12, 16};
-static __maybe_unused uint16_t link_speed[] = {25, 50, 80, 160};
+static const __maybe_unused uint16_t link_width[] = {0, 1, 2, 4, 8, 12, 16};
+static const __maybe_unused uint16_t link_speed[] = {25, 50, 80, 160};
 
 static const
 struct smu_temperature_range __maybe_unused smu11_thermal_policy[] =

drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega12_hwmgr.c

@@ -52,8 +52,8 @@
 
 #define LINK_WIDTH_MAX				6
 #define LINK_SPEED_MAX				3
-static int link_width[] = {0, 1, 2, 4, 8, 12, 16};
-static int link_speed[] = {25, 50, 80, 160};
+static const int link_width[] = {0, 1, 2, 4, 8, 12, 16};
+static const int link_speed[] = {25, 50, 80, 160};
 
 static int vega12_force_clock_level(struct pp_hwmgr *hwmgr,
 		enum pp_clock_type type, uint32_t mask);

drivers/gpu/drm/amd/pm/powerplay/hwmgr/vega20_hwmgr.c

@@ -57,8 +57,8 @@
 
 #define LINK_WIDTH_MAX				6
 #define LINK_SPEED_MAX				3
-static int link_width[] = {0, 1, 2, 4, 8, 12, 16};
-static int link_speed[] = {25, 50, 80, 160};
+static const int link_width[] = {0, 1, 2, 4, 8, 12, 16};
+static const int link_speed[] = {25, 50, 80, 160};
 
 static void vega20_set_default_registry_data(struct pp_hwmgr *hwmgr)
 {

drivers/gpu/drm/amd/pm/swsmu/smu13/smu_v13_0.c

@@ -72,8 +72,8 @@ MODULE_FIRMWARE("amdgpu/aldebaran_smc.bin");
 #define PCIE_LC_SPEED_CNTL__LC_CURRENT_DATA_RATE_MASK 0xC000
 #define PCIE_LC_SPEED_CNTL__LC_CURRENT_DATA_RATE__SHIFT 0xE
 
-static int link_width[] = {0, 1, 2, 4, 8, 12, 16};
-static int link_speed[] = {25, 50, 80, 160};
+static const int link_width[] = {0, 1, 2, 4, 8, 12, 16};
+static const int link_speed[] = {25, 50, 80, 160};
 
 int smu_v13_0_init_microcode(struct smu_context *smu)
 {