pinctrl: sophgo: introduce generic probe function

pinctrl: sophgo: introduce generic probe function

Since different series of the Sophgo chip share a common pinctrl data
structure. It is necessary to add a common probe function to alloc
the this data structure. Add pctrl_init callback to allow soc to perform
its own initialization.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Link: https://lore.kernel.org/20250211051801.470800-5-inochiama@gmail.com
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>