wayland: Add target sysroot scanner m4 macro

With the new aclocals process, accesses to the macros is a lot stricter and the native macros are not used. We need to ensure the modified macros are used in target builds to get the correct scanner functionality. Inserting the native macro into the target is the correct thing to do in this case.

This resolves build failures in libva.

---

index 0f08cac..604b7f4 100644
@@ -34,3 +34,7 @@ do_install_append_class-native() {
       -e 's,$PKG_CONFIG,pkg-config-native,g' \
       -i ${D}/${datadir}/aclocal/wayland-scanner.m4
 }
+
+sysroot_stage_all_append_class-target () {
+	cp ${STAGING_DATADIR_NATIVE}/aclocal/wayland-scanner.m4 ${SYSROOT_DESTDIR}/${datadir}/aclocal/
+}