iwlwifi: mvm: fix the spatial reuse parsing for HE_TRIG PPDUs

The spatial reuse 4 words fields are fetched from the HE-SIGA
by the firmware and propagated to the driver through the
Rx info. This is useful to populate the radiotap header.

We were looking at the wrong place in the firmware data and
got bogus values. Fix that.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Fixes: bdf180c8 ("iwlwifi: mvm: change PHY data RX for HE radiotap")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>