When building this driver for an architecture that does not support
CONFIG_PM_SLEEP, such as hexagon, the following warnings occur:

  drivers/soc/mediatek/mtk-svs.c:1481:12: error: unused function 'svs_suspend' [-Werror,-Wunused-function]
  static int svs_suspend(struct device *dev)
             ^
  drivers/soc/mediatek/mtk-svs.c:1515:12: error: unused function 'svs_resume' [-Werror,-Wunused-function]
  static int svs_resume(struct device *dev)
             ^
  2 errors generated.

This happens because SIMPLE_DEV_PM_OPS uses SET_SYSTEM_SLEEP_PM_OPS,
which evaluates to nothing when CONFIG_PM_SLEEP is not set, leaving the
functions unused in the eyes of the compiler.

This problem was rectified in commit 1a3c7bb0 ("PM: core: Add new
*_PM_OPS macros, deprecate old ones") with new macros. Use
DEFINE_SIMPLE_DEV_PM_OPS to fix the warning while not changing
svs_pm_ops when CONFIG_PM_SLEEP is set.

Fixes: 681a02e9 ("soc: mediatek: SVS: introduce MTK SVS engine")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20220622175649.1856337-1-nathan@kernel.orgSigned-off-by: Matthias Brugger <matthias.bgg@gmail.com>