lavu: Bump version for the 12bit Planar YUV support

doc/APIchanges

@@ -13,6 +13,9 @@ libavutil:     2015-08-28
 
 API changes, most recent first:
 
+2016-xx-xx - xxxxxxx - lavu 55.22.0 - pixfmt.h
+  Add AV_PIX_FMT_YUV(420,422,444)P12.
+
 2016-xx-xx - xxxxxxx - lavc 59.27.0 - avcodec.h
   Add FF_PROFILE_HEVC_REXT, the extended pixel format profile for HEVC.
 

libavutil/version.h

@@ -54,7 +54,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR 55
-#define LIBAVUTIL_VERSION_MINOR 21
+#define LIBAVUTIL_VERSION_MINOR 22
 #define LIBAVUTIL_VERSION_MICRO  0
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \