serial: sh-sci: Convert to DEFINE_SIMPLE_DEV_PM_OPS()

serial: sh-sci: Convert to DEFINE_SIMPLE_DEV_PM_OPS()

Convert the Renesas SuperH SCI(F) serial port driver from
SIMPLE_DEV_PM_OPS() to DEFINE_SIMPLE_DEV_PM_OPS() and pm_sleep_ptr().
This lets us drop the __maybe_unused annotations from its suspend and
resume callbacks, and reduces kernel size in case CONFIG_PM or
CONFIG_PM_SLEEP is disabled.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/a5628fe028362ae3f8729021a7864dd39f7869bf.1752086885.git.geert+renesas@glider.be
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>