Add some GPIO debug support:  /sys/kernel/debug/omap_gpio dumps the state
of all GPIOs that have been claimed, including basic IRQ info if relevant.
Tested on 24xx, 16xx.

Includes minor bugfixes:  recording IRQ trigger mode (this should probably
be a genirq patch), adding missing space to non-wakeup warning
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>