x11r7/xkeyboard-config: select xkbcomp

xkeyboard-config uses xkbcomp at runtime, so select it.

closes #5704.

package/x11r7/xkeyboard-config/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_XKEYBOARD_CONFIG
 	bool "xkeyboard-config"
+	select BR2_PACKAGE_XAPP_XKBCOMP
 	help
 	  keyboard configuration database for X