wifi: iwlwifi: mvm: unite sta_modify_disable_tx flows

wifi: iwlwifi: mvm: unite sta_modify_disable_tx flows

These flows are the same in both MLD API and the current API,
except for the commands that are being sent during this flows.
Instead of checking each time before calling these floews
what API we use and then call the correct function, call always the old
one, which in turn will call the new one in case we're using the MLD
API.

Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Signed-off-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://lore.kernel.org/r/20230328104948.5692d8dea9be.Ib1882b2c2f0b0603abc4b7d4a0ecc45cd1fbf9a7@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>