pinctrl: implement PINMUX_MAP_SYS_HOG

This is the same as PINMUX_MAP_PRIMARY_SYS_HOG, except that it allows
you to specify a particular control device.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>