Merge tag 'iwlwifi-next-for-kalle-2019-04-18-2' of git://git.kernel.org/pub/scm/linux...

Third batch of patches intended for v5.2

* Bump the 20000-series FW API version supported;
* Work on the new debugging infra continues;
* One clean-up to prevent a bogus warning with clang;
* A small cleanup in the PCI ID list;
* Work on new hardware continues;
* RTT confidence indication support for FTM;
* An improvement in HE rate-scaling;