vc4: Use named parameters for the NEON inline asm.

This makes the asm code more intelligible and clarifies the functional
change in the next commit.

(commit message and commit squashing by anholt)
(cherry picked from commiti 522f6884)
[Emil: apply the patch to vc4_tiling_lt.c instead of v3d_cpu_tiling.h]
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>

Conflicts:
        src/broadcom/common/v3d_cpu_tiling.h