soc: nordic: vpr: add workaround for MSTATUS.MIE not waking VPR up

Due to HW issue, VPR needs to keep MSTATUS.MIE enabled during sleep.
Otherwise, interrupts will not wake it up.

Signed-off-by: Marcin Szymczyk <marcin.szymczyk@nordicsemi.no>
3 files changed