iwlwifi: mvm: move AP-specific code to right function

There's no need for the common MAC context function to have an
if on AP mode, the values can be overridden in the AP-specific
function later. Clean that up by adding the full command as a
new parameter to the AP-specific function, and doing it there.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>