common: Re-support EGL 1.4 by using EGLImageKHR when needed
EGLImage was added to core EGL in version 1.5, but was available as an extension in 1.4 as EGLImageKHR, all of the rest of kmscube is EGL 1.4 compatible except this typedef. Allow kmscube to be EGL 1.4 compatible again by checking for EGL 1.5 and if not available falling back to the old typedef name.
Signed-off-by: Andrew F. Davis afd@ti.com