iwlwifi: multiple force reset mode

Provide the function to perform different type of uCode reset/reload operation.
When uCode detect error and can not fix itself, this iwl_force_reset()
function allow driver to perform the necessary reset/reload functions and help
to bring uCode back to normal operation state.

Currently only 2 type of force reset are available:
 - reset radio
 - reload firmware

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>