16 bpc fixed point (RGBA16) framebuffer support for core and AMD.

[Ville Syrjälä]

On Fri, Mar 19, 2021 at 10:03:12PM +0100, Mario Kleiner wrote:
> Hi,
> 
> this patch series adds the fourcc's for 16 bit fixed point unorm
> framebuffers to the core, and then an implementation for AMD gpu's
> with DisplayCore.
> 
> This is intended to allow for pageflipping to, and direct scanout of,
> Vulkan swapchain images in the format VK_FORMAT_R16G16B16A16_UNORM.
> I have patched AMD's GPUOpen amdvlk OSS driver to enable this format
> for swapchains, mapping to DRM_FORMAT_XBGR16161616:
> Link: https://github.com/kleinerm/pal/commit/a25d4802074b13a8d5f7edc96ae45469ecbac3c4

We should also add support for these formats into igt.a Should 
be semi-easy by just adding the suitable float<->uint16
conversion stuff.

-- 
Ville Syrjälä
Intel