msm8974: Add support for ADC driver

Add support for vadc driver to read battery ID, input voltage
& APIs to set max usb & battery current.

Change-Id: Ie92b9797991f73687234a8c4efa3052f4f10f7b2
diff --git a/dev/pmic/pm8x41/rules.mk b/dev/pmic/pm8x41/rules.mk
index 1c3bbc1..af7f394 100644
--- a/dev/pmic/pm8x41/rules.mk
+++ b/dev/pmic/pm8x41/rules.mk
@@ -3,4 +3,5 @@
 INCLUDES += -I$(LOCAL_DIR)/include
 
 OBJS += \
-	$(LOCAL_DIR)/pm8x41.o
+	$(LOCAL_DIR)/pm8x41.o \
+	$(LOCAL_DIR)/pm8x41_adc.o