QcomModulePkg: Correct the dtbo idx

dtbo_idx should be the index of dt_table_entry in DTBO partition,
not the partition number in GPT.

Change-Id: I8a2b1c208afe262ffc2783b87fc10b70be084c74
diff --git a/QcomModulePkg/Include/Library/LocateDeviceTree.h b/QcomModulePkg/Include/Library/LocateDeviceTree.h
index f62466b..76bb0e6 100644
--- a/QcomModulePkg/Include/Library/LocateDeviceTree.h
+++ b/QcomModulePkg/Include/Library/LocateDeviceTree.h
@@ -269,5 +269,5 @@
 DeviceTreeValidate (UINT8 *DeviceTreeBuff,
                     UINT32 PageSize,
                     UINT32 *DeviceTreeSize);
-
+INT32 GetDtboIdx (VOID);
 #endif