omxvideodec: fix OMX flags on header buffer

The header (SPS/PPS) buffer should have the CODECONFIG flag and not the
ENDOFFRAME one as it's not actually a frame.
7 jobs for codecconfig-master in 16 minutes and 28 seconds (queued for 2 seconds)
latest
Status Job ID Name Coverage
  Preparation
passed #448837
gst indent

00:00:17

passed #448836
manifest

00:00:41

 
  Build
passed #448838
build fedora x86_64

00:06:37

passed #448839
build nodebug fedora x86_64

00:05:55

passed #448840
build static fedora x86_64

00:11:19

passed #448841
build static nodebug fedora x86_64

00:11:30

 
  Integrate
passed #448842
documentation

00:04:15