iwlwifi: mvm: check IWL_UCODE_TLV_API_SCD_CFG in API and not in capa

IWL_UCODE_TLV_API_SCD_CFG is a new API and hence, check if
enabled in the correct field.

Fixes: 0294d9ee ("iwlwifi: mvm: let the firmware configure the scheduler")
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>