Disable the TWL4030_MODIRQ_KEYPAD symbol and remove all its uses.
It's not needed any more now that platform_get_irq() works for
these keypad devices.

Also remove inappropriate board-specific Kconfig dependencies.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>