iwlwifi: fw api: fix PHY data 2/3 position

In AX210 devices, the PHY data wasn't actually reported, but now
that it's going to be reported it turns out that the position is
supposed to be the other way around, fix that.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20200424182643.06de959301f5.I544c353a8a811f107bd66d168e37920237ecf071@changeid