ffmpeg: bump version to 3.3.1

Signed-off-by: Vicente Olivert Riera <Vincent.Riera@imgtec.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/ffmpeg/ffmpeg.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256 599e7f7c017221c22011c4037b88bdcd1c47cd40c1e466838bc3c465f3e9569d  ffmpeg-3.3.tar.xz
+sha256 b702a7fc656ac23e276b8c823a2f646e4e6f6309bb2788435a708e69bea98f2f  ffmpeg-3.3.1.tar.xz

package/ffmpeg/ffmpeg.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-FFMPEG_VERSION = 3.3
+FFMPEG_VERSION = 3.3.1
 FFMPEG_SOURCE = ffmpeg-$(FFMPEG_VERSION).tar.xz
 FFMPEG_SITE = http://ffmpeg.org/releases
 FFMPEG_INSTALL_STAGING = YES