package/ffmpeg: add optional support for libsoxr

Now that libsoxr no longer depends on ffmpeg, we can actually use
libsoxr in ffmpeg.

See:

  https://trac.ffmpeg.org/wiki/FFmpeg%20and%20the%20SoX%20Resampler

for some details.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ffmpeg/ffmpeg.mk

@@ -376,6 +376,13 @@ else
 FFMPEG_CONF_OPTS += --disable-libopenmpt
 endif
 
+ifeq ($(BR2_PACKAGE_LIBSOXR),y)
+FFMPEG_CONF_OPTS += --enable-libsoxr
+FFMPEG_DEPENDENCIES += libsoxr
+else
+FFMPEG_CONF_OPTS += --disable-libsoxr
+endif
+
 ifeq ($(BR2_PACKAGE_SPEEX),y)
 FFMPEG_CONF_OPTS += --enable-libspeex
 FFMPEG_DEPENDENCIES += speex