Platform/Sgi: Add Initial SMBIOS support

SMBIOS provides basic hardware and firmware configuration information
through table-driven data structure. This patch adds SMBIOS driver
support that allows for installation of multiple SMBIOS types. Also add
SMBIOS Type0 (BIOS Information) table, that include information about
BIOS vendor name, version, SMBIOS version and other information related
to BIOS.

Change-Id: Iac9c196dd4f0b7dd76f48d9d2cede0f524c8b9f3
Signed-off-by: Pranav Madhu <pranav.madhu@arm.com>