ffmpeg: fix dependencies

The ffmpeg binary does not require swscale, but ffplay needs it.

ffserver needs fork().

Signed-off-by: Benoît Thébaudeau <benoit@wsystem.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/ffmpeg/Config.in

@@ -25,7 +25,6 @@ config BR2_PACKAGE_FFMPEG_NONFREE
 
 config BR2_PACKAGE_FFMPEG_FFMPEG
 	bool "Build ffmpeg (the command line application)"
-	select BR2_PACKAGE_FFMPEG_SWSCALE
 	default y
 	help
 	  FFmpeg is a very fast video and audio converter.
@@ -36,6 +35,7 @@ config BR2_PACKAGE_FFMPEG_FFMPEG
 
 config BR2_PACKAGE_FFMPEG_FFPLAY
 	bool "Build ffplay"
+	select BR2_PACKAGE_FFMPEG_SWSCALE
 	select BR2_PACKAGE_SDL
 	help
 	  FFplay is a very simple and portable media player using the
@@ -44,6 +44,7 @@ config BR2_PACKAGE_FFMPEG_FFPLAY
 
 config BR2_PACKAGE_FFMPEG_FFSERVER
 	bool "Build ffserver"
+	depends on BR2_USE_MMU # fork()
 	help
 	  FFserver is a streaming server for both audio and video.