drm/i915: include gen 2 in HAS_128_BYTE_Y_TILING()

drm/i915: include gen 2 in HAS_128_BYTE_Y_TILING()

Gen 2 platforms actually have 128-byte Y-tile, it's just different from
the 128-byte Y-tile on i945+. Make the HAS_128_BYTE_Y_TILING() feature
check macro and its usage slightly less convoluted by including gen 2 in
it.

i915_tiling_ok() would strictly not need changing, but separate the if
clauses to emphasize gen 2 X-tile also being 128 bytes.

Suggested-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://lore.kernel.org/r/41bf9d67a11f38f4ab0f82740f38d5c8fe0bb58b.1760094361.git.jani.nikula@intel.com