[why]
creating a generic helper for AMD specific PSR-SU sink validation.
Moving the function to the power module to reference it across all
OS.

[how]
- drop PSRSU specific sink validation helper and move to power
  module by reading PSR version and other PSR caps
- call the new helper from linux DM (amdgpu_dm_psr)
Acked-by: Pavle Kotarac <Pavle.Kotarac@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: David Zhang <dingchen.zhang@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>