contrib: fix x246 for iOS x86-64

Change-Id: I3dfb7d9a4ec1056caacf755ccf06b46854c6e66b

contrib/src/x264/rules.mak

@@ -53,7 +53,7 @@ x264: x264-$(X264_HASH).tar.xz .sum-x264
 ifdef HAVE_ANDROID
 	cd $< && $(HOSTVARS) AS="$(CC)" ./configure $(X264CONF)
 else
-ifdef HAVE_IOS
+ifeq ($(IOS_TARGET_PLATFORM),iPhoneOS)
 	cd $< && $(HOSTVARS) ASFLAGS="$(CFLAGS)" ./configure $(X264CONF)
 else
 	cd $< && $(HOSTVARS) ./configure $(X264CONF)