pinctrl: Implementation of the generic scmi-pinctrl driver

scmi-pinctrl driver implements pinctrl driver interface and using
SCMI protocol to redirect messages from pinctrl subsystem SDK to
SCMI platform firmware, which does the changes in HW.

Co-developed-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@epam.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Reviewed-by: Andy Shevchenko <andy@kernel.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Link: https://lore.kernel.org/r/20240418-pinctrl-scmi-v11-4-499dca9864a7@nxp.com
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>