drm: Add drm_rotation_90_or_270()

We have intel_rotation_90_or_270() in i915 to check if the rotation is
90 or 270 degrees. Similar checks are elsewhere in drm, so let's move
the helper into a central place and use it everwhere.

v2: Drop the BIT()
    Convert all new intel_rotation_90_or_270() calls
    Deal with superfluous code shuffling

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (v1)
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1474907460-10717-2-git-send-email-ville.syrjala@linux.intel.com
diff --git a/drivers/gpu/drm/i915/intel_fbc.c b/drivers/gpu/drm/i915/intel_fbc.c
index faa6762..afc040b 100644
--- a/drivers/gpu/drm/i915/intel_fbc.c
+++ b/drivers/gpu/drm/i915/intel_fbc.c
@@ -84,7 +84,7 @@
 {
 	int w, h;
 
-	if (intel_rotation_90_or_270(cache->plane.rotation)) {
+	if (drm_rotation_90_or_270(cache->plane.rotation)) {
 		w = cache->plane.src_h;
 		h = cache->plane.src_w;
 	} else {