The fw already supports scan api v14 and the firmware version that
supports only v13 was not published, so we can remove support for v13 in
the driver.

Signed-off-by: Tova Mussai <tova.mussai@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200417131727.11883315579a.I4f59100e457c1079c5e4c90e4930d1fa62b7ddd7@changeid