Hi,
Not sure why this was backported in the first place, but if so you'd also need 1fb1abc83636 ("um: Fix build w/o CONFIG_PM_SLEEP").
I think b58294ce1a8a ("um: Allow PM with suspend-to-idle") should just be reverted, but picking up the fix for it also works.
Robot keeps reporting to me that it's broken :)
Thanks, johannes