ARM: 6664/1: AT91: Use macros for gpio_to_irq/irq_to_gpio

Replace the static inline functions for gpio_to_irq/irq_to_gpio so that
they can be used in static initialisers.

Signed-off-by: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>