smbios: implement smbios support for mach-virt

smbios: implement smbios support for mach-virt

This patch generates smbios tables for ARM mach-virt. Also add
CONFIG_SMBIOS=y for ARM default config.

Acked-by: Gabriel Somlo <[email protected]>
Tested-by: Gabriel Somlo <[email protected]>
Reviewed-by: Laszlo Ersek <[email protected]>
Reviewed-by: Shannon Zhao <[email protected]>
Tested-by: Leif Lindholm <[email protected]>
Signed-off-by: Wei Huang <[email protected]>
Message-id: 1440615870[email protected]
[PMM: Added missing braces around an if().]
Reviewed-by: Peter Maydell <[email protected]>
Signed-off-by: Peter Maydell <[email protected]>