[Xf86-video-armsoc] [PATCH 0/1] Fallback to 24 bit depth if 32 bit depth is not

[armsoc-bugs at arm.com]

[commit pushed to repo - appologies - external code review is not in place]
The max depth of some drm drivers (such as the pl111) is 24 bits. An attempt
to create a framebuffer with 32 bit depth on such drivers will be rejected.
Applications which use ARGB8888 will therefore fall back to blitting rather
than flipping.
This change will fall back to 24 bit depth if 32 bit depth is not supported.
Page flipping will then be possible on these framebuffer requests.