wifi: iwlwifi: mvm: make iwl_mvm_mac_ctxt_send_beacon() static

We never needed this to be non-static, that was just an
artifact of the development process. Make it static.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230414130637.3c018c15f948.I87fd1aee288f33312a7206492608002d4e8e213e@changeid


Signed-off-by: Johannes Berg <johannes.berg@intel.com>