panfrost: Rework linear<--->tiled conversions

panfrost: Rework linear<--->tiled conversions

There's a lot going on here (it's a ton of commits squashed together
since otherwise this would be impossible to review...)

1. We have a fast path for linear->tiled for whole (aligned) tiles, but we
have to use a slow path for unaligned accesses. We can get a pretty
major win for partial updates by using this slow path simply on the
borders of the update region, and then hit the fast path for the
tile-aligned interior. This does require some shuffling.

2. Mark the LUTs constant, which allows the compiler to inline them,
which pairs well with loop unrolling (eliminating the memory accesses
and just becoming some immediates.. which are not as immediate on
aarch64 as I'd like..)

3. Add fast path for bpp1/2/8/16. These use the same algorithm and we
have native types for them, so may as well get the fast path.

4. Drop generic path for bpp != 1/2/8/16, since these formats are
generally awful and there's no way to tile them efficienctly and
honestly there's not a good reason too either. Lima doesn't support any
of these formats; Panfrost can make the opinionated choice to make them
linear.

5. Specialize the unaligned routines. They don't have to be fully
generic, they just can't assume alignment. So now they should be nearly
as fast as the aligned versions (which get some extra tricks to be even
faster but the difference might be neglible on some workloads).

6. Specialize also for the size of the tile, to allow 4x4 tiling as well
as 16x16 tiling. This allows compressed textures to be efficiently tiled
with the same routines (so we add support for tiling ASTC/ETC textures
while we're at it)

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Reviewed-by: Vasily Khoruzhick <anarsoul@gmail.com>
Tested-by: Vasily Khoruzhick <anarsoul@gmail.com> #lima on Mali400
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/merge_requests/3414>