drm/amd/swSMU: add callback to set AC/DC power source (v2)

This is needed to tell the SMU firmware what state is in
in certain cases.  DC mode does not allow overclocking
for example.

v2: split Evan's original patch (Alex)

Bug: https://gitlab.freedesktop.org/drm/amd/issues/1043Reviewed-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Evan Quan <evan.quan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/powerplay/inc/amdgpu_smu.h

@@ -570,6 +570,7 @@ struct pptable_funcs {
 	int (*override_pcie_parameters)(struct smu_context *smu);
 	uint32_t (*get_pptable_power_limit)(struct smu_context *smu);
 	int (*disable_umc_cdr_12gbps_workaround)(struct smu_context *smu);
+	int (*set_power_source)(struct smu_context *smu, enum smu_power_src_type power_src);
 };
 
 int smu_load_microcode(struct smu_context *smu);

drivers/gpu/drm/amd/powerplay/smu_internal.h

@@ -211,4 +211,7 @@ static inline int smu_send_smc_msg(struct smu_context *smu, enum smu_message_typ
 #define smu_disable_umc_cdr_12gbps_workaround(smu) \
 	((smu)->ppt_funcs->disable_umc_cdr_12gbps_workaround ? (smu)->ppt_funcs->disable_umc_cdr_12gbps_workaround((smu)) : 0)
 
+#define smu_set_power_source(smu, power_src) \
+	((smu)->ppt_funcs->set_power_source ? (smu)->ppt_funcs->set_power_source((smu), (power_src)) : 0)
+
 #endif