iwlwifi: pcie: free some DMA memory earlier

iwlwifi: pcie: free some DMA memory earlier

In gen3, after firmware is alive, we no longer need the
firmware and image loader images, only the context info
itself and PRPH info/scratch need to remain.

Call iwl_pcie_ctxt_info_gen3_free() appropriately in the
alive callback (iwl_trans_pcie_gen2_fw_alive()) with a new
argument indicating whether it can free everything or only
partially.

The context info and PRPH scratch are also not needed after
PNVM load, but we don't have a good hook for freeing after
that, so keep them for now.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618105614.8230d91a46c1.Ia7db71e5e6265ca87363f1481eac1bc3bbebb15c@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>