ir3/a6xx: account for resinfo return size dependency on IBO_0_FMT

On a6xx resinfo returns size in bytes divided by IBO_0_FMT format size (not just size in dwords), we have to shift it back to NIR meaning which is size in bytes.

Make freedreno use 16b buffers when they are supported in order to be able to depend on hardware capabilities when lowering ssbo size.

Fixes: ce1a381e "turnip: enable VK_KHR_16bit_storage on A650"

Fixes cts tests:

 dEQP-VK.ssbo.unsized_array_length.float_offset_explicit_size
 dEQP-VK.ssbo.unsized_array_length.float_no_offset_whole_size
 dEQP-VK.compute.basic.write_multiple_unsized_arr_single_invocation

and many more