drm/i915/fbc: Allow FBC with Yf tiling

drm/i915/fbc: Allow FBC with Yf tiling

FBC+Yf tiling seems to work just fine, and unlike with linear
the hardware does appear to correctly calculate the CFB stride
with using the override stride on both cfl and glk. So no need
for any additional tweaks.

Cc: Uma Shankar <uma.shankar@intel.com> #v2
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924141330.1515-1-ville.syrjala@linux.intel.com
Reviewed-by: Uma Shankar <uma.shankar@intel.com>