iwlwifi: Set w-pointer upon resume according to SN

During D3 state, FW may send packets.
As a result, "write" queue pointer will be incremented by FW.
Upon resume from D3, driver should adjust its shadows of "write" and "read"
pointers to the value reported by FW.

1. Keep TID used during wowlan configuration.
2. Upon resume, set driver's "write" and "read" queue pointers
	to the value reported by FW.

Signed-off-by: Alex Malamud <alex.malamud@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>