net: wwan: iosm: Keep device at D0 for s2idle case

net: wwan: iosm: Keep device at D0 for s2idle case

We are seeing spurious wakeup caused by Intel 7560 WWAN on AMD laptops.
This prevent those laptops to stay in s2idle state.

>From what I can understand, the intention of ipc_pcie_suspend() is to
put the device to D3cold, and ipc_pcie_suspend_s2idle() is to keep the
device at D0. However, the device can still be put to D3hot/D3cold by
PCI core.

So explicitly let PCI core know this device should stay at D0, to solve
the spurious wakeup.

Signed-off-by: Kai-Heng Feng <[email protected]>
Signed-off-by: David S. Miller <[email protected]>