iwlwifi: move uCode flags handling to op_mode

The uCode flags modification is op_mode dependent
since the P2P config is an op-mode config.

This also fixes P2P enabling: due to the uCode
loading code shuffle moving the SKU check before
the EEPROM was read it was always false and would
always disable PAN/P2P.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>