target: msm8996: Check for ENABLE_DISPLAY flag

This flag is required for fastboot oem select-display-panel command to work
and update it to kernel command line.

Change-Id: I01fc745e161d39a9261f4479764e31d6468266ea
diff --git a/target/msm8996/rules.mk b/target/msm8996/rules.mk
index a9d5093..ed6bae0 100644
--- a/target/msm8996/rules.mk
+++ b/target/msm8996/rules.mk
@@ -27,8 +27,11 @@
 ifeq ($(DISPLAY_SCREEN),0)
  DEFINES += DISPLAY_SPLASH_SCREEN=0
 else
+ifeq ($(ENABLE_DISPLAY),1)
+ DEFINES += ENABLE_DISPLAY=1
  DEFINES += DISPLAY_SPLASH_SCREEN=1
 endif
+endif
 
 DEFINES += DISPLAY_TYPE_MIPI=1
 DEFINES += DISPLAY_TYPE_DSI6G=1