x11r7/xserver_xorg: breaks with shared cache

The package overrides CFLAGS, so disable shared cache.

package/x11r7/xserver_xorg-server/xserver_xorg-server.mk

@@ -9,6 +9,7 @@ XSERVER_XORG_SERVER_SOURCE = xorg-server-$(XSERVER_XORG_SERVER_VERSION).tar.bz2
 XSERVER_XORG_SERVER_SITE = http://xorg.freedesktop.org/releases/individual/xserver
 XSERVER_XORG_SERVER_AUTORECONF = NO
 XSERVER_XORG_SERVER_INSTALL_STAGING = YES
+XSERVER_XORG_SERVER_USE_CONFIG_CACHE = NO # overrides CFLAGS
 
 ifeq ($(BR2_PACKAGE_XSERVER_xorg),y)
 XSERVER_XORG_MESA_DEPS:=mesa3d