xfree86: Report Present as a built-in module

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

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Keith Packard <keithp@keithp.com>

hw/xfree86/loader/loadmod.c

@@ -840,6 +840,9 @@ static const char *compiled_in_modules[] = {
     "dri2",
 #if DRI3
     "dri3",
+#endif
+#if PRESENT
+    "present",
 #endif
     NULL
 };