* vulkan: RDNA3 static mat-vec rows above four columns
On RDNA3 above four columns a static 4 rows for all types benches faster than
the default.
* vulkan: RDNA3 static mat-vec-id rows
mul_mat_vec_id has no column dimension to switch on. On my Strix Halo machine,
a static 4 is faster here than the defaults across types and batch sizes.
