freedreno: Handle DRM_FORMAT_MOD_INVALID in shared code

freedreno: Handle DRM_FORMAT_MOD_INVALID in shared code

layout_resource_for_modifier() needs to handle DRM_FORMAT_MOD_INVALID
as well, since src/gallium/frontends/dri/dri2.c uses this to indicate
"no modifier" when it's called through the older non-modifier entry
points.

This is similar to 334788d4 ("freedreno: allow INVALID modifier") but
for the generic implementation.

Fixes: 98910626 ("freedreno/a6xx: Implement layout for DRM_FORMAT_MOD_QCOM_COMPRESSED")
Closes: #3154
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5611>