PCMCIA: sa11x0: assabet: convert to use new irq/gpio management

Convert Assabet socket driver to use the new irq/gpio management.
This is slightly more involved because we have to touch the private
platform header file to modify the GPIO bitmasks to be GPIO numbers.

Acked-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>