drm/amd/display: Implement CRTC CRC for DCE110

Implement the timing generator hooks for configure_crc and get_crc.
Also implement is_tg_enabled, as configure_crc uses it.

Signed-off-by: Leo (Sunpeng) Li <sunpeng.li@amd.com>
Reviewed-by: Tony Cheng <Tony.Cheng@amd.com>
Reviewed-by: Harry Wentland <Harry.Wentland@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>