anv: Enable "permanent" compression for immutable format images

anv: Enable "permanent" compression for immutable format images

This commit extends our support of color compression to surfaces without
the VK_IMAGE_CREATE_MUTABLE_FORMAT_BIT set.  These images will never have
an image view created with a different format then the one set at image
creation time so it's safe to always use compression.  We still bail if the
image is used as a storage image because that sometimes ends up using a
different format.

Reviewed-by: Topi Pohjolainen <topi.pohjolainen@intel.com>