Allow touch to use a key code to sync touch events

This is needed to make touch work on the x86-64 emulator target
though I have seen the key code used on other devices as a way to
synchronize touch events.

Change-Id: I31a3cc56e6470f2c707641b537140e44f5e686aa
diff --git a/gui/Android.mk b/gui/Android.mk
index 81cd559..afaa5da 100644
--- a/gui/Android.mk
+++ b/gui/Android.mk
@@ -39,7 +39,10 @@
 
 #TWRP_EVENT_LOGGING := true
 ifeq ($(TWRP_EVENT_LOGGING), true)
-LOCAL_CFLAGS += -D_EVENT_LOGGING
+    LOCAL_CFLAGS += -D_EVENT_LOGGING
+endif
+ifneq ($(TW_USE_KEY_CODE_TOUCH_SYNC),)
+    LOCAL_CFLAGS += -DTW_USE_KEY_CODE_TOUCH_SYNC=$(TW_USE_KEY_CODE_TOUCH_SYNC)
 endif
 
 ifneq ($(TW_NO_SCREEN_BLANK),)
@@ -49,7 +52,7 @@
     LOCAL_CFLAGS += -DTW_NO_SCREEN_TIMEOUT
 endif
 ifeq ($(HAVE_SELINUX), true)
-LOCAL_CFLAGS += -DHAVE_SELINUX
+    LOCAL_CFLAGS += -DHAVE_SELINUX
 endif
 ifeq ($(TW_OEM_BUILD), true)
     LOCAL_CFLAGS += -DTW_OEM_BUILD