iwlwifi: fw: fix the enums in the rate scaling API

We don't need the _enum suffix.
Also refer to &enum iwl_tlc_mng_vht_he_types instead
of %IWL_TLC_MNG_VALID_VHT_HE_TYPES_\*

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>