xwayland: Fix "-force-xrandr-emulation"

Commit 7cdcdfea introduced a new command line option
"-force-xrandr-emulation", however it is missing from the
ddxProcessArgument().

As a result, trying to use that command option would result in a error:

(EE) Unrecognized option: -force-xrandr-emulation

Make sure "-force-xrandr-emulation" is accounted for in Xwayland's
ddxProcessArgument().

Signed-off-by: Olivier Fourdan <ofourdan@redhat.com>
Fixes: 7cdcdfea - xwayland: Add -force-xrandr-emulation switch

hw/xwayland/xwayland.c

@@ -230,6 +230,9 @@ ddxProcessArgument(int argc, char *argv[], int i)
         touchEmulatePointer = FALSE;
         return 1;
     }
+    else if (strcmp(argv[i], "-force-xrandr-emulation") == 0) {
+        return 1;
+    }
     else if (strcmp(argv[i], "-geometry") == 0) {
         CHECK_FOR_REQUIRED_ARGUMENTS(1);
         return 2;