ARM: sa1100: explicitly register sa11x0-pcmcia devices

Simplify the code by getting rid of the conditional automatic
registration of the sa11x0 PCMCIA interfaces in sa1100_init(), and
require all platforms to explicitly call sa11x0_register_pcmcia().
Only one platform (iPAQ) is affected by this change.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>