partition_parser: Add gpt_exist function

The new function is used to check if the partition table is GPT

Change-Id: I19dabbe5b756faa3be841407d05ddc23c2914e08
diff --git a/platform/msm_shared/partition_parser.c b/platform/msm_shared/partition_parser.c
index 881d2a0..5cca931 100644
--- a/platform/msm_shared/partition_parser.c
+++ b/platform/msm_shared/partition_parser.c
@@ -59,7 +59,7 @@
 unsigned int vfat_count = 0;
 
 struct partition_entry partition_entries[NUM_PARTITIONS];
-unsigned gpt_partitions_exist = 0;
+static unsigned gpt_partitions_exist = 0;
 unsigned partition_count = 0;
 
 unsigned int partition_read_table()
@@ -957,3 +957,8 @@
 
 	return 0;
 }
+
+bool partition_gpt_exists()
+{
+	return (gpt_partitions_exist != 0);
+}