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.

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>