Add APIs to store/load BIOS tables

This commit implements C++ APIs to store a PLDM BIOS table into
persistent storage, and to load the same back into memory. This commit
also defines C structs representing the different BIOS tables.

Signed-off-by: Deepak Kodihalli <dkodihal@in.ibm.com>
Change-Id: I4a771a368c6931464f45ae4a8f467b579c7a5d74