Allow disalbing ALSA using WITHOUT_ALSA_SOUND=1

src/xpdev/GNUmakefile

@@ -9,8 +9,10 @@ ifneq ($(os),win32)
 endif
 
 CFLAGS	+=	-DSOUNDCARD_H_IN=$(shell if [ -f /usr/include/sys/soundcard.h ] ; then echo 1 ; elif [ -f /usr/include/soundcard.h ] ; then echo 2 ; elif [ -f /usr/include/linux/soundcard.h ] ; then echo 3 ; else echo 0 ; fi) -I. $(XPDEV_CFLAGS)
-ifeq ($(shell if [ -f /usr/include/alsa/asoundlib.h ] ; then echo YES ; fi),YES)
-	CFLAGS	+=	-DUSE_ALSA_SOUND
+ifndef WITHOUT_ALSA_SOUND
+	ifeq ($(shell if [ -f /usr/include/alsa/asoundlib.h ] ; then echo YES ; fi),YES)
+		CFLAGS	+=	-DUSE_ALSA_SOUND
+	endif
 endif
 MT_CFLAGS	+=	$(XPDEV-MT_CFLAGS)