omxplayer: make samba support configureable
omxplayer: make samba support configureable

* samba depends on libpam and it might be useful to disable support
  for it in DISTROs without pam in DISTRO_FEATURES
* disable it by default

Signed-off-by: Martin Jansa <516df3ff67e1fa5d153800b15fb204c0a1a389dc@gmail.com>

leon-anavi/meta-raspberrypi,schnitzeltony/meta-raspberrypi,schnitzeltony/meta-raspberrypi,leon-anavi/meta-raspberrypi,kraj/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,kraj/meta-raspberrypi,agherzan/meta-raspberrypi,leon-anavi/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,agherzan/meta-raspberrypi,schnitzeltony/meta-raspberrypi,kraj/meta-raspberrypi