target: add api to get battery info

Add api to get battery's voltage and add safeguards such as
refusing to flash if minimum battery levels are not present or
be bypass if the device doesn't have a battery

Change-Id: Ie9fc45cd2d3a5f588acedef4fd9b0ffdcb2eae24
diff --git a/target/msm8952/init.c b/target/msm8952/init.c
index 0c711de..ebf0349 100644
--- a/target/msm8952/init.c
+++ b/target/msm8952/init.c
@@ -57,6 +57,7 @@
 #include <boot_device.h>
 #include <secapp_loader.h>
 #include <rpmb.h>
+#include <smem.h>
 
 #include "target/display.h"
 
@@ -669,3 +670,8 @@
 
 	crypto_init_params(&ce_params);
 }
+
+uint32_t target_get_pmic()
+{
+	return PMIC_IS_PMI8950;
+}