iwlwifi: pcie: support loading FW with extended mem range

Toggle the LMPM_CHICK register when writing chunks into the FW's extended
SRAM. This tells the FW to put the chunk into a different memory space.

Signed-off-by: Arik Nemtsov <arikx.nemtsov@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>