qtwayland: drop xcomposite-egl, xcomposite-glx packageconfig for mx8

qtwayland: drop xcomposite-egl, xcomposite-glx packageconfig for mx8

NXP dropped native X11 support for i.MX 8(X).

with xcomposite-glx:
qtwayland fails in configure with:

| ERROR: Feature 'xcomposite-glx' was enabled, but the pre-condition 'features.wayland-client && features.opengl && !features.opengles2 && features.xlib && libs.xcomposite && libs.glx' failed.
| ERROR: Feature 'xcomposite-glx' was enabled, but the pre-condition 'features.wayland-server && features.opengl && !features.opengles2 && libs.xcomposite && libs.glx' failed.

with xcomposte-egl:
qtwayland fails during compile starting with:

| .../qwaylandxcompositeeglclientbufferintegration.cpp:140:59: error: cannot convert 'Display*' {aka '_XDisplay*'} to 'EGLNativeDisplayType' {aka 'wl_display*'}
|       integration->mEglDisplay = eglGetDisplay(integration->mDisplay);
|                                                ~~~~~~~~~~~~~^~~~~~~~

Signed-off-by: Max Krummenacher <max.krummenacher@toradex.com>