pinctrl: renesas: Allow the compiler to optimize away sh_pfc_pm

The conversion to DEFINE_NOIRQ_DEV_PM_OPS() lost the ability of the
compiler to optimize away the struct dev_pm_ops object when it is not
needed.

Fix this by replacing the use of pm_sleep_ptr() by a custom wrapper.

Fixes: 727eb02e ("pinctrl: renesas: Switch to use DEFINE_NOIRQ_DEV_PM_OPS() helper")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/6238a78e32fa21f0c795406b6cba7bce7af92577.1708513940.git.geert+renesas@glider.be