drm/i915/fbc: s/lines/height/

Use the more customary name 'height' instead of 'lines'.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240705145254.3355-10-ville.syrjala@linux.intel.com


Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>