drm/amdgpu: add new HDP CG flags

HDP 5.0 supports SRAM power gating. all the LS (Light Sleep)/
DS (Deep Sleep)/SD (Shut Down) modes are supported. However,
only one of these modes can be enabled at one time.

There is no dynamic power mode switch support. clock/power gating
has to be disabled before making any power mode change.

Signed-off-by: Hawking Zhang <[e-mail]>
Reviewed-by: Alex Deucher <[e-mail]>
Signed-off-by: Alex Deucher <[e-mail]>

drivers/gpu/drm/amd/include/amd_shared.h

···
 #define AMD_CG_SUPPORT_DRM_MGCG			(1 << 22)
 #define AMD_CG_SUPPORT_DF_MGCG			(1 << 23)
 #define AMD_CG_SUPPORT_VCN_MGCG			(1 << 24)
+#define AMD_CG_SUPPORT_HDP_DS			(1 << 25)
+#define AMD_CG_SUPPORT_HDP_SD			(1 << 26)
 /* PG flags */
 #define AMD_PG_SUPPORT_GFX_PG			(1 << 0)
 #define AMD_PG_SUPPORT_GFX_SMG			(1 << 1)