iwlwifi: mvm: purge the BSS table upon firmware load

When the firmware is loaded, its internal timer (GP2) is
reset and all the time_sync in the BSS table is now
unusable. Ask cfg80211 to purge the BSS table.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20201209231352.1b703b6f4c05.I0b5c51aa87e86c964e2eae6d959a96e232840ef5@changeid


Signed-off-by: Luca Coelho <luciano.coelho@intel.com>