drm/amd/display: Change locking of registers when flipping frames.

- Introduce GRPH_UPDATE_LOCK around programming surface flip.
- Remove the now unused graphic surface lock.
- Add macros to get and set four registers
- both immediate and H Retrace should not be enabled at the same time

Signed-off-by: Andrew Wong <[email protected]>
Reviewed-by: Tony Cheng <[email protected]>
Acked-by: Harry Wentland <[email protected]>
Signed-off-by: Alex Deucher <[email protected]>
6 files changed