[PATCH] GPIO API: S3C2410 wrapper cleanup

this one adds an #include <asm/arch/regs-gpio.h>.
Tested by Roman Moravcik on s3c2440.

Based on the discussion last december
(http://lkml.org/lkml/2006/12/20/243

), this patch
 - fixes comment and includes in gpio.h
 - adds the gpio_to_irq definition for S3C2400
 - includes asm/arch/regs-gpio.h for pin direction
   definitions

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>