SSB PCI core driver: use new SPROM data structure

Switch the SSB PCI core driver to the new SPROM data structure now that
the old one has been removed.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Acked-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>