iwlwifi: cfg: use antenna diversity with all AX101 devices

We were erroneously only setting the tx_with_siso_diversity flag in
the Qu B-step configurations for AX101 devices, though we should do
it on all configurations.  Add the flag to the other two
configurations, namely Qu C-step and QuZ.

Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200306151129.1cd986ef467c.Idc0b111475ae3d38b68ae062613c080b574e33e1@changeid