gstreamer1.0-plugins-bad: Fix GL/GLES configuration

gstreamer1.0-plugins-bad: Fix GL/GLES configuration

* Replace --disable/enable-gl with the individual EGL, GLES, GL switches
  (--disable-gl turns off GL support entirely)
* Put the default opengl packageconfig into its own variable to make it
  easier for distros and BSP layers to define what to use (GL, GLES,
  or neither)
* Add libglu as a dependency for desktop GL
* Patch configure.ac to ensure libraries are only searched and linked to
  if the corresponding API isn't disabled (this prevents cases where
  libgstgl is linked to GLU even though desktop GL is dis- and GLES
  enabled)

(From OE-Core rev: 7bf062f2e2b92c2401fa2386b6281aae023b21a8)

Signed-off-by: Carlos Rafael Giani <dv@pseudoterminal.org>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>