Revert "wifi: iwlwifi: bump FW API to 90 for BZ/SC devices"

Revert the API version bump, the kernel doesn't actually have
all the code to deal with that version yet.

Fixes: 653a90f6

 ("wifi: iwlwifi: bump FW API to 90 for BZ/SC devices")
Link: https://msgid.link/20240419085147.cd756fadab03.Ibccbb65be8e05b516cae1b9fb27a959662f9f51a@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>