ARM: tegra: select PINCTRL_TEGRA124 for Tegra124 SoC

The pincontrol driver for Tegra124 is build through config
PINCTRL_TEGRA124. Select this config option whenever Tegra124
SoC is enabled.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Stephen Warren <swarren@nvidia.com>