Why:
Screen sometimes would have artifacts or blink once at the time when bpp
is dynamically changed.

How:
1. Changed to update PPS infopacket in frame mode instead of immediate mode
   since other updates for bpp change are double-buffered.
2. Changed double-buffering enablement programming for DCN30 as advised by
ASIC team
Reviewed-by: Wenjing Liu <wenjing.liu@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Bing Guo <Bing.Guo@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>