dvb.media_addon: Let C++ use C99 math features.

- This get rids of the complain "'UINT64_C' was not declared in this scope" and
  allows us to remove the (now superflous) declaration of UINT64_C.
- No functional change intended.

src/add-ons/media/media-add-ons/dvb/Jamfile

@@ -8,6 +8,7 @@ UseHeaders [ FDirName $(ffmpegHeaders) libavcodec ] ;
 UseHeaders [ FDirName $(ffmpegHeaders) libavformat ] ;
 UseHeaders [ FDirName $(ffmpegHeaders) libavutil ] ;
 
+SubDirC++Flags -D__STDC_CONSTANT_MACROS -Wno-deprecated-declarations ;
 
 Addon dvb.media_addon :
 	DVBCard.cpp

src/add-ons/media/media-add-ons/dvb/MediaFormat.cpp

@@ -27,7 +27,6 @@
 #include <stdio.h>
 #include "MediaFormat.h"
 
-#define UINT64_C(c) (c ## ULL)
 extern "C" {
   #include "avcodec.h"