contrib: update ffmpeg to 4.4.2

Change-Id: Icaaeefc9cdeb084e56192e4bd5154912122a6abd

contrib/src/ffmpeg/SHA512SUMS

-f2cc4eddef135009c13bb99f4c134085e4daa6835736756b78874a9c971bbac2e7fd2ffde3f511d2ce22b141c3524d86e3b84b72987ba204c7c460b1933f2bf3  ffmpeg-n4.4.tar.gz
+0c184e960a234cd08cbc3539885d00e83b17b28b2b49c1c55b8dc0f6d22f88183a48900285ac01e63a051bd12b003dd131f171f669b2051abeba8a3c3411975d  ffmpeg-n4.4.2.tar.gz

contrib/src/ffmpeg/package.json

 {
     "name": "ffmpeg",
-    "version": "n4.4",
+    "version": "n4.4.2",
     "url": "https://github.com/FFmpeg/FFmpeg/archive/__VERSION__.tar.gz",
     "deps": [
         "vpx",

contrib/src/ffmpeg/rules.mak

-FFMPEG_HASH := n4.4
+FFMPEG_HASH := n4.4.2
 FFMPEG_URL := https://git.ffmpeg.org/gitweb/ffmpeg.git/snapshot/$(FFMPEG_HASH).tar.gz
 
 PKGS+=ffmpeg