Merge tag 'arcpgu-updates-2019.12.16' of github.com:abrodkin/linux into drm-next

Clean-up and fixes for FourCC handling in ARC PGU.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
From: Alexey Brodkin <Alexey.Brodkin@synopsys.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CY4PR1201MB01204228B5788F0A6619FE45A1510@CY4PR1201MB0120.namprd12.prod.outlook.com