sunxi: Print soc-id from sram controller for sun8i boards

As the need for various magic sram pokes has shown this maybe useful
info to have. e.g. this shows one of my a23 tablets having an id of
1661 rather then the usual 1650 for the a23.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Ian Campbell <ijc@hellion.org.uk>