libpldm: Add API to decode package header info

This patch provides API to decode the firmware update package header
information and also do basic validation.

The API works with DSP0267_1.1.0, DSP0267_1.0.1 and DSP0267_1.0.0.

Tested: Unit tests passed

Signed-off-by: Tom Joseph <rushtotom@gmail.com>
Change-Id: I208a219cd4b9c9b9869eb3e286259b2f51206487
diff --git a/libpldm/base.h b/libpldm/base.h
index 451137d..8644a5a 100644
--- a/libpldm/base.h
+++ b/libpldm/base.h
@@ -91,6 +91,8 @@
 #define PLDM_VERSION_0 0
 #define PLDM_CURRENT_VERSION PLDM_VERSION_0
 
+#define PLDM_TIMESTAMP104_SIZE 13
+
 /** @struct pldm_msg_hdr
  *
  * Structure representing PLDM message header fields