drm/amd/display: Use optc32 instead of optc30 in DC

Change DC to use optc32, which uses REG_UPDATE instead of REG_SET.
REG_SET clears OTG_H_TIMING_DIV_MODE_MANUAL which must be set to 1 in
some specific HDMI configurations.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Charlene Liu <charlene.liu@amd.com>
Acked-by: Rodrigo Siqueira <rodrigo.siqueira@amd.com>
Signed-off-by: Ovidiu Bunea <ovidiu.bunea@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>