Our HE doesn't support it so never set HE 160 stbc

Fixes: 3e467b8e ("iwlwifi: rs-fw: enable STBC in he correctly")
Signed-off-by: Mordechay Goodstein <mordechay.goodstein@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210411124418.550fd1903eb7.I8ddbc2f87044a5ef78d916c9c59be797811a1b7f@changeidSigned-off-by: Luca Coelho <luciano.coelho@intel.com>