rpi-default-providers: remove vlc,ffmpeg PREFFERED_PROVIDER

Switch to defaulting to OE core ffmpeg &
meta-openembedded vlc.

Upgrades to newer rpi-distro VLC version
in an OE environment have proven to be
tedious due to all the PI foundation patches.

Some patches aren't fully pushed into github
and require updates to build.

Maintaining patches have also proven to be unstable.

Defualt to stable builds of both so that.

Peoples builds aren't broken. If rpi-distro
rpi-distro version of ffmpeg & vlc wanted
users may switch by setting PREFFERED_PROVIDER.

Signed-off-by: Vincent Davis Jr <vince@underview.tech>

conf/machine/include/rpi-default-providers.inc

@@ -7,10 +7,6 @@ PREFERRED_PROVIDER_virtual/libgles2 ?= "${@bb.utils.contains("MACHINE_FEATURES",
 PREFERRED_PROVIDER_virtual/libgl ?= "${@bb.utils.contains("MACHINE_FEATURES", "vc4graphics", "mesa", "mesa-gl", d)}"
 PREFERRED_PROVIDER_virtual/mesa ?= "${@bb.utils.contains("MACHINE_FEATURES", "vc4graphics", "mesa", "mesa-gl", d)}"
 PREFERRED_PROVIDER_virtual/libgbm ?= "${@bb.utils.contains("MACHINE_FEATURES", "vc4graphics", "mesa", "mesa-gl", d)}"
-PREFERRED_PROVIDER_vlc ?= "rpidistro-vlc"
-PREFERRED_PROVIDER_ffmpeg ?= "rpidistro-ffmpeg"
-PREFERRED_PROVIDER_libav ?= "rpidistro-ffmpeg"
-PREFERRED_PROVIDER_libpostproc ?= "rpidistro-ffmpeg"
 PREFERRED_PROVIDER_jpeg ?= "jpeg"
 
 PREFERRED_PROVIDER_virtual/libomxil ?= "userland"