drm/i915/fbc: Remove stale FIXME

Remove the old tales about 90/270 degree rotation
effectively preventing FBC. That hasn't been true since
we stopped demanding the fence is present in
commit 691f7ba58d ("drm/i915/display/fbc: Make fences
a nice-to-have for GEN9+")

Also fix up the multiline comment formatting while at it.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220916165206.1499-2-ville.syrjala@linux.intel.com
Reviewed-by: Luca Coeho <luciano.coelho@intel.com>

drivers/gpu/drm/i915/display/intel_fbc.c

@@ -1010,7 +1010,8 @@ static bool intel_fbc_is_fence_ok(const struct intel_plane_state *plane_state)
 {
 	struct drm_i915_private *i915 = to_i915(plane_state->uapi.plane->dev);
 
-	/* The use of a CPU fence is one of two ways to detect writes by the
+	/*
+	 * The use of a CPU fence is one of two ways to detect writes by the
 	 * CPU to the scanout and trigger updates to the FBC.
 	 *
 	 * The other method is by software tracking (see
@@ -1020,12 +1021,6 @@ static bool intel_fbc_is_fence_ok(const struct intel_plane_state *plane_state)
 	 * Note that is possible for a tiled surface to be unmappable (and
 	 * so have no fence associated with it) due to aperture constraints
 	 * at the time of pinning.
-	 *
-	 * FIXME with 90/270 degree rotation we should use the fence on
-	 * the normal GTT view (the rotated view doesn't even have a
-	 * fence). Would need changes to the FBC fence Y offset as well.
-	 * For now this will effectively disable FBC with 90/270 degree
-	 * rotation.
 	 */
 	return DISPLAY_VER(i915) >= 9 ||
 		(plane_state->flags & PLANE_HAS_FENCE &&