tty: serial: qcom_geni: avoid duplicate struct member init

When -Woverride-init is enabled in a build, gcc points out that
qcom_geni_serial_pm_ops contains conflicting initializers:

drivers/tty/serial/qcom_geni_serial.c:1586:20: error: initialized field overwritten [-Werror=override-init]
 1586 |         .restore = qcom_geni_serial_sys_hib_resume,
      |                    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/tty/serial/qcom_geni_serial.c:1586:20: note: (near initialization for 'qcom_geni_serial_pm_ops.restore')
drivers/tty/serial/qcom_geni_serial.c:1587:17: error: initialized field overwritten [-Werror=override-init]
 1587 |         .thaw = qcom_geni_serial_sys_hib_resume,
      |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Open-code the initializers with the version that was already used,
and use the pm_sleep_ptr() method to deal with unused ones,
in place of the __maybe_unused annotation.

Fixes: 35781d83

 ("tty: serial: qcom-geni-serial: Add support for Hibernation feature")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20221215165453.1864836-1-arnd@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>