radeonsi: fix a regression in integer cube map handling

radeonsi: fix a regression in integer cube map handling

A recent commit fixed the case of 8888 integer cube maps, which need the
workaround of replacing the data format with USCALED/SSCALED. However,
this broke the case of non-8888 integer cube maps; those still need the
fix of shifting the texture coordinates.

Fixes KHR-GL45.texture_gather.plain-gather-int-cube-array and similar.

Fixes: 6fb0c1013b35 ("radeonsi: workaround for gather4 on integer cube maps")
Reviewed-by: Marek Olšák <marek.olsak@amd.com>