amdgpu/dc: another round of dce/dcn construct cleanups.

This removes any remaining pointless return codepaths from the
DCE code.

Signed-off-by: Dave Airlie <airlied@redhat.com>
Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Connect DC resource to FBC compressor

- Connected DC resource to FBC compressor,
- Initial Implementation of FBC for Stoney/Carrizo
- Code is currently guarded with "ENABLE_FBC" compile time flag

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: remove unneeded FBC hw programming code

- Removed uneeded FBC code.
- Initial placeholder for FBC implementation on stoney/carrizo

Signed-off-by: Bhawanpreet Lakha <Bhawanpreet.Lakha@amd.com>
Reviewed-by: Roman Li <Roman.Li@amd.com>
Acked-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/dc: Add dc display driver (v2)

Supported DCE versions: 8.0, 10.0, 11.0, 11.2

v2: rebase against 4.11

Signed-off-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>