spi: spi-nxp-fspi: enable runtime pm for fspi

Enable the runtime PM in fspi driver.
Also for system PM, On some board like i.MX8ULP-EVK board,
after system suspend, IOMUX module will lost power, so all
the pinctrl setting will lost when system resume back, need
driver to save/restore the pinctrl setting.

Signed-off-by: Han Xu <han.xu@nxp.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Link: https://patch.msgid.link/20250428-flexspipatch-v3-2-61d5e8f591bc@nxp.com


Signed-off-by: Mark Brown <broonie@kernel.org>