package/x11r7/xdriver_xf86-video-savage: don't override XDRIVER_XF86_VIDEO_SAVAGE_CONF_OPTS

XDRIVER_XF86_VIDEO_SAVAGE_CONF_OPTS is wrongly overridden in a
conditional since commit c38103f2fe793ea5257d3f5b8413ece7a5c60538

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/x11r7/xdriver_xf86-video-savage/xdriver_xf86-video-savage.mk

@@ -13,7 +13,7 @@ XDRIVER_XF86_VIDEO_SAVAGE_AUTORECONF = YES
 XDRIVER_XF86_VIDEO_SAVAGE_DEPENDENCIES = xserver_xorg-server libdrm xorgproto
 
 ifeq ($(BR2_PACKAGE_MESA3D_DRI_DRIVER),)
-XDRIVER_XF86_VIDEO_SAVAGE_CONF_OPTS = --disable-dri
+XDRIVER_XF86_VIDEO_SAVAGE_CONF_OPTS += --disable-dri
 endif
 
 $(eval $(autotools-package))