pinctrl: tegra: add pinmux controller driver for Tegra124

This adds a driver for the Tegra124 pinmux, and required
parameterization data for Tegra124.

The driver uses the common Tegra pincontrol driver utility
functions to implement the majority of the driver.

This driver is not compatible with the earlier NVIDIA's SoCs,
hence add new compatibile as "nvidia,tegra124-pinmux".

Originally written by Ashwini Gguhe.
Thierry:
 - Cleanups in patches.
ldewangan:
 - Fix some entries for groups.
 - Fix MUX enums and group sequence.

Signed-off-by: Ashwini Ghuge <aghuge@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Tested-by: Stephen Warren <swarren@nvidia.com>
CC: Thierry Reding <treding@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>