iwlwifi: dbg_ini: make fill_range handler accept generic range pointer

Make fill_range handler of iwl_dump_ini_mem_ops accept a generic range
pointer. It is needed for future support in fifos dumping.

Signed-off-by: Shahar S Matityahu <shahar.s.matityahu@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>