Delete unused VideoType enum values

Bug: None
Change-Id: I4294cdda93ebca44fa43de63e37d5d1fdeb2fa62
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/198120
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32975}

common_video/libyuv/include/webrtc_libyuv.h

@@ -32,17 +32,12 @@ enum class VideoType {
   kI420,
   kIYUV,
   kRGB24,
-  kABGR,
   kARGB,
-  kARGB4444,
   kRGB565,
-  kARGB1555,
   kYUY2,
   kYV12,
   kUYVY,
   kMJPEG,
-  kNV21,
-  kNV12,
   kBGRA,
 };