i2c: hix5hd2: Remove #ifdef guards for PM related functions

i2c: hix5hd2: Remove #ifdef guards for PM related functions

Use the new PM macros for the suspend and resume functions to be
automatically dropped by the compiler when CONFIG_PM or
CONFIG_PM_SLEEP are disabled, without having to use #ifdef guards.

This has the advantage of always compiling these functions in,
independently of any Kconfig option. Thanks to that, bugs and other
regressions are subsequently easier to catch.

Note that this driver should probably use the
DEFINE_RUNTIME_DEV_PM_OPS() macro, which would allow the devices to be
runtime-suspended on system suspend.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20230722115046.27323-8-paul@crapouillou.net
Signed-off-by: Andi Shyti <andi.shyti@kernel.org>