[PATCH] ARM: OMAP: support set_irq_type()

This updates IRQ triggering code to be a closer match for other ARMs:
 - Adds support for the standard ARM-Linux set_irq_type() call.
 - Reports errors on unsupported triggering modes (e.g. nothing except
   16xx GPIOs can trigger on both edges) and on bogus wakeup requests.
 - Deprecates the OMAP-only omap_set_gpio_edge_ctrl() call.
 - Removes many of the "sparse" warnings from the GPIO code.
 - Modifies the smc91x driver so it knows which OMAP boards use falling
   edge triggers (vs rising, like everything else).
Later patches can remove the deprecation warnings and then the OMAP-only
version of that standard call.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Tony Lindgren <tony@atomide.com>