panfrost: XMLify Midgard properties

In a long journey to a full XML representation of mali_shader_meta,
let's start with the fourth word, containing some shader properties.
This is a translation from panfrost-job.h, with the exception of
widening the uniform buffer count field [1]

The other noteworthy change is combining the unknown 0x20 flag with the
WRITES_Z flag to form a 2-bit depth source. This papers over the fact
that the blob zeroes this field for non-fragment shaders. Given the
proximity, this is a reasonable guess and avoids an ugly "is_fragment"
bit.

[1] Justified by the increased limit advertised by the Vulkan blob
(maxDescriptorSetUniformBuffers on
https://vulkan.gpuinfo.org/displayreport.php?id=5602#limits). Not
actually supported in Panfrost right now.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6440>