egl,QueryWaylandBufferWL: return EGL_TEXTURE_* as EGL_TEXTURE_FORMAT

problem:
    the native buffer format was returned (HAL_PIXEL_FORMAT_*)
fix:
    map HAL_PIXEL_FORMAT_* to EGL_TEXTURE_*

Signed-off-by: Adrian Negreanu <adrian.m.negreanu@intel.com>
Merge pull request #133 from groleo/eglQueryWaylandBufferWL

egl,QueryWaylandBufferWL: return EGL_TEXTURE_* as EGL_TEXTURE_FORMAT