xfree86: Report DRI3 as a built-in module

This is so that drivers can do a runtime check that DRI3 is available,
similar to existing runtime checks performed by the drivers for DRI and
DRI2.

v2: Only add DRI3 to the list if the module was actually built into the
server (Mark Kettenis).

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mark Kettenis <mark.kettenis@xs4all.nl>
Signed-off-by: Keith Packard <keithp@keithp.com>

hw/xfree86/loader/loadmod.c

@@ -838,6 +838,9 @@ static const char *compiled_in_modules[] = {
     "extmod",
     "dri",
     "dri2",
+#if DRI3
+    "dri3",
+#endif
     NULL
 };