drm/amd/display: Wrap OTG disable workaround with FIFO control

drm/amd/display: Wrap OTG disable workaround with FIFO control

[Why]
The DIO FIFO will underflow if we turn off the OTG before we turn
off the FIFO.

Since this happens as part of the OTG workaround and we don't reset
the FIFO afterwards we see the error persist.

[How]
Add disable FIFO before the disable CRTC and enable FIFO after enabling
the CRTC.

Reviewed-by: Syed Hassan <Syed.Hassan@amd.com>
Acked-by: Jasdeep Dhillon <jdhillon@amd.com>
Signed-off-by: Nicholas Kazlauskas <nicholas.kazlauskas@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>