mplayer: disable parallel builds (make -jX)

The build system races with itself when building the internal vidix stuff
(x86 only), so use MAKE1.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/multimedia/mplayer/mplayer.mk

@@ -71,7 +71,7 @@ $(MPLAYER_DIR)/.configured: $(MPLAYER_DIR)/.unpacked
 	touch $@
 
 $(MPLAYER_DIR)/$(MPLAYER_BINARY): $(MPLAYER_DIR)/.configured
-	$(MAKE) -C $(MPLAYER_DIR)
+	$(MAKE1) -C $(MPLAYER_DIR)
 	touch -c $@
 
 $(TARGET_DIR)/$(MPLAYER_TARGET_BINARY): $(MPLAYER_DIR)/$(MPLAYER_BINARY)