target: project: 8996: Enable reboot module

Reboot module & usage of PON registers for reboot reason is enabled and
remove the reboot_device, shutdown_device apis from target code.

Change-Id: Id80cf16a95a3e6ed9ba38e1bd9cd33f34b431e11
diff --git a/project/msm8996.mk b/project/msm8996.mk
index 2669b56..e885f30 100644
--- a/project/msm8996.mk
+++ b/project/msm8996.mk
@@ -82,3 +82,6 @@
 
 #SCM call before entering DLOAD mode
 DEFINES += PLATFORM_USE_SCM_DLOAD=1
+
+#Enable the external reboot functions
+ENABLE_REBOOT_MODULE := 1