libomxil-bellagio: inherit class `pkgconfig` to stage pkg-config file `libomxil-bella...

libomxil-bellagio: inherit class `pkgconfig` to stage pkg-config file `libomxil-bellagio.pc`

`libomxil-bellagio` distributes a pkg-config file [1] which is only put to the following location with the following content.

	$ more angstrom-dev/sysroots/armv7a-angstrom-linux-gnueabi/usr/lib/pkgconfig/libomxil-bellagio.pc
	prefix=/usr
	exec_prefix=/usr
	libdir=/usr/lib
	includedir=/usr/include
	toolsdir=/usr/bin
	pluginsdir=${libdir}/bellagio

	Name: libomxil
	Description: OpenMAX Integration Layer library
	Version: 0.9.2.1
	Libs: -L${libdir} -lomxil-bellagio
	Cflags: -I${includedir} -I${includedir}/bellagio

To make it useful for crosscompiling inherit `pkgconfig.bbclass`.

[1] http://omxil.git.sourceforge.net/git/gitweb.cgi?p=omxil/omxil;a=blob;f=libomxil-bellagio.pc.in;h=abae71bf4ade80e26b28a755f214a96285fd5c47;hb=772f0eca88b242ffb5469e8e381c63ce1f7cd3e1

Signed-off-by: Paul Menzel <paulepanter@users.sourceforge.net>
Signed-off-by: Khem Raj <raj.khem@gmail.com>