panfrost: Use implementation-specific tile size

panfrost: Use implementation-specific tile size

The physical tile buffer size (and hence the maximum available tilebuffer size)
are implementation-defined. Track this information on the device so we can
correctly select tile sizes, instead of hardcoding the value for Midgard.

Implementation values are pulled from the "Tile bits/pixel" row of the public
Mali data sheet [1]. That row lists the maximum number of bits available for a
pixel given the maximum tile size and pipelining. For currently supported
hardware (v9 and older), that maximum tile size is 16x16. So those values should
be multiplied by (16 * 16 * 2) / 8 to get the physical size in bytes.

This may improve Bifrost/Valhall performance on workloads using multiple render
targets. It also gets us ready for the dazzling array of tile sizes available
with v10.

[1] https://developer.arm.com/documentation/102849/latest/

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/17432>