package/ffmpeg: add optional support for libvpl

Added with commit
http://git.videolan.org/?p=ffmpeg.git;a=commit;h=7158f1e64d9b76afea78537a35c465447df0cff8

"It will fail to run configure script if both libmfx and libvpl are
enabled.

It is recommended to use oneVPL for new work, even for currently
available hardwares"

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/ffmpeg/ffmpeg.mk

@@ -321,11 +321,14 @@ else
 FFMPEG_CONF_OPTS += --disable-libbluray
 endif
 
-ifeq ($(BR2_PACKAGE_INTEL_MEDIASDK),y)
-FFMPEG_CONF_OPTS += --enable-libmfx
+ifeq ($(BR2_PACKAGE_LIBVPL),y)
+FFMPEG_CONF_OPTS += --enable-libvpl --disable-libmfx
+FFMPEG_DEPENDENCIES += libvpl
+else ifeq ($(BR2_PACKAGE_INTEL_MEDIASDK),y)
+FFMPEG_CONF_OPTS += --disable-libvpl --enable-libmfx
 FFMPEG_DEPENDENCIES += intel-mediasdk
 else
-FFMPEG_CONF_OPTS += --disable-libmfx
+FFMPEG_CONF_OPTS += --disable-libvpl --disable-libmfx
 endif
 
 ifeq ($(BR2_PACKAGE_RTMPDUMP),y)