mailbox: qcom-ipcc: Fix -Wunused-function with CONFIG_PM_SLEEP=n

mailbox: qcom-ipcc: Fix -Wunused-function with CONFIG_PM_SLEEP=n

When CONFIG_PM_SLEEP is not set, there is a warning that
qcom_ipcc_pm_resume() is unused:

  drivers/mailbox/qcom-ipcc.c:258:12: error: 'qcom_ipcc_pm_resume' defined but not used [-Werror=unused-function]
    258 | static int qcom_ipcc_pm_resume(struct device *dev)
        |            ^~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors

Commit 1a3c7bb08826 ("PM: core: Add new *_PM_OPS macros, deprecate old
ones") reworked the PM_OPS macros to avoid this problem. Use
NOIRQ_SYSTEM_SLEEP_PM_OPS directly so that qcom_ipcc_pm_resume() always
appears to be used to the compiler, even though it will be dead code
eliminated in the !CONFIG_PM_SLEEP case.

Fixes: c25f77899753 ("mailbox: qcom-ipcc: Log the pending interrupt during resume")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Sibi Sankar <quic_sibis@quicinc.com>
Signed-off-by: Jassi Brar <jaswinder.singh@linaro.org>