Platform/Sgi: Add SMBIOS Type19 Table

Add the SMBIOS type 19 table (Memory Array Mapped Addr) that includes
information about the address mapping for a Physical Memory Array.

Signed-off-by: Pranav Madhu <pranav.madhu@arm.com>
Reviewed-by: Thomas Abraham <thomas.abraham@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>