ARM: tegra: add tegra_gpio_table and tegra_gpio_config

To give one place to setup the pins that are used as GPIOs instead
of as their pinmuxed functions. Specifying enabled as false explicitly
disables the gpio mode of that pin (if left on by firmware).

This should remove the need for calling these from specific drivers and
thus reduce tegra-specific code from them.

Signed-off-by: Olof Johansson <olof@lixom.net>
Acked-by: Erik Gilling <konkers@android.com>