platform: msm_shared: Enable compilation of gpio.c

Enable compilation of gpio.c for Ferrum.

Change-Id: I65ed218d99c5aa50c6e106478a075dce504c092c
diff --git a/platform/msm_shared/rules.mk b/platform/msm_shared/rules.mk
index 59454aa..7fb5ef3 100755
--- a/platform/msm_shared/rules.mk
+++ b/platform/msm_shared/rules.mk
@@ -416,7 +416,8 @@
 			$(LOCAL_DIR)/bam.o \
 			$(LOCAL_DIR)/qpic_nand.o \
 			$(LOCAL_DIR)/scm.o \
-			$(LOCAL_DIR)/dev_tree.o
+			$(LOCAL_DIR)/dev_tree.o \
+			$(LOCAL_DIR)/gpio.o
 endif
 
 ifeq ($(ENABLE_BOOT_CONFIG_SUPPORT), 1)