libva: check for "opengl" feature

libva: check for "opengl" feature

In case "opengl" is missing from DISTRO_FEATURES, libva fails to satisfy
its dependencies. The dependency check is done by BitBake when
meta-world-pkgdata gathers information about all available packages
during image builds, even if libva isn't included in the build. This
patch makes libva recipe be skipped if the "opengl" DISTRO_FEATURE isn't
found.

(From OE-Core rev: a78c420c4a2cf298e790b71b564a9f52949b966a)

Signed-off-by: Ismo Puustinen <ismo.puustinen@intel.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>