ssb: Fix build for non-PCIhost

This fixes a build error when PCMCIA-host support is built,
but PCI-host support is disabled.
Hell, who on earth would use such a weird configuration. :D

drivers/built-in.o: In function `ssb_attr_sprom_store':
(.text+0x1c4b79): undefined reference to `ssb_devices_freeze'
drivers/built-in.o: In function `ssb_attr_sprom_store':
(.text+0x1c4bb3): undefined reference to `ssb_devices_thaw'
make[1]: *** [.tmp_vmlinux1] Error 1

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>