i965: Fix "handle nir_intrinsic_image_size"

i965: Fix "handle nir_intrinsic_image_size"

I pushed a half-baked version of "i965: handle nir_intrinsic_image_size" by
accident. Not having the Reviewed-by: tags on the last two commits should
have been a red flag but I somehow missed it after the QA check.

This patch should fix image-size for non-int images. I will add support to
the piglit test for all the other image types.

Sorry for the noise.

Signed-off-by: Martin Peres <martin.peres@linux.intel.com>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>