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/include/partition_parser.h b/platform/msm_shared/include/partition_parser.h
index 0508e00..25a73ca 100644
--- a/platform/msm_shared/include/partition_parser.h
+++ b/platform/msm_shared/include/partition_parser.h
@@ -162,6 +162,7 @@
 unsigned long long partition_get_offset(int index);
 unsigned int partition_read_table();
 unsigned int write_partition(unsigned size, unsigned char *partition);
+bool partition_gpt_exists();
 
 /* For Debugging */
 void partition_dump(void);