ARM: OMAP: Update gpio-switch framework

- Support for in-kernel notifications

  Some boards require state-switch notifications from GPIOs
  that are also exposed to user-space through the gpio-switch
  framework.

- Support for board-specific debounce values
- Support for switches defined from board-specific file
- Support for GPIO banks that can trigger on both rising
  and falling edges

Signed-off-by: Juha Yrjola <juha.yrjola@solidboot.com>