drm/amd/display: Move CLK_BASE_INNER macro

This macro is specificly used by RV1. Move it to the appropriate
location.

Signed-off-by: Eric Yang <Eric.Yang2@amd.com>
Reviewed-by: Aric Cyr <Aric.Cyr@amd.com>
Acked-by: Leo Li <sunpeng.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>