If CONFIG_PM_SLEEP is not set.

make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-, will fail:

drivers/ufs/host/ufs-mediatek.c: In function ‘ufs_mtk_vreg_fix_vcc’:
drivers/ufs/host/ufs-mediatek.c:688:46: warning: format ‘%u’ expects argument of type ‘unsigned int’, but argument 4 has type ‘long unsigned int’ [-Wformat=]
    snprintf(vcc_name, MAX_VCC_NAME, "vcc-opt%u", res.a1);
                                             ~^   ~~~~~~
                                             %lu
drivers/ufs/host/ufs-mediatek.c: In function ‘ufs_mtk_system_suspend’:
drivers/ufs/host/ufs-mediatek.c:1371:8: error: implicit declaration of function ‘ufshcd_system_suspend’; did you mean ‘ufs_mtk_system_suspend’? [-Werror=implicit-function-declaration]
  ret = ufshcd_system_suspend(dev);
        ^~~~~~~~~~~~~~~~~~~~~
        ufs_mtk_system_suspend
drivers/ufs/host/ufs-mediatek.c: In function ‘ufs_mtk_system_resume’:
drivers/ufs/host/ufs-mediatek.c:1386:9: error: implicit declaration of function ‘ufshcd_system_resume’; did you mean ‘ufs_mtk_system_resume’? [-Werror=implicit-function-declaration]
  return ufshcd_system_resume(dev);
         ^~~~~~~~~~~~~~~~~~~~
         ufs_mtk_system_resume
cc1: some warnings being treated as errors

The declaration of func "ufshcd_system_suspend()" depends on
CONFIG_PM_SLEEP, so the function wrapper ufs_mtk_system_suspend() should
wrapped by CONFIG_PM_SLEEP too.

Link: https://lore.kernel.org/r/20220619115432.205504-1-renzhijie2@huawei.com
Fixes: 3fd23b8d ("scsi: ufs: ufs-mediatek: Fix the timing of configuring device regulators")
Reported-by: Hulk Robot <hulkci@huawei.com>
Reviewed-by: Stanley Chu <stanley.chu@mediatek.com>
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>