net: vertexcom: mse102x: Use DEFINE_SIMPLE_DEV_PM_OPS

net: vertexcom: mse102x: Use DEFINE_SIMPLE_DEV_PM_OPS

This macro has the advantage over SET_SYSTEM_SLEEP_PM_OPS that we don't
have to care about when the functions are actually used.

Also make use of pm_sleep_ptr() to discard all PM_SLEEP related
stuff if CONFIG_PM_SLEEP isn't enabled.

Signed-off-by: Stefan Wahren <wahrenst@gmx.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240827191000.3244-2-wahrenst@gmx.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>