Add pkgconfig files needed by other projects (for example newer libva
packages look for egl.pc file).

Pkgconfig files added by this patch:
 * egl.pc
 * gl.pc
 * gles_cm.pc
 * glesv2.pc

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>