Merge tag 'mt76-for-kvalo-2019-06-27' of https://github.com/nbd168/wireless

mt76 patches for 5.3

* use NAPI polling for tx cleanup on mt7603/mt7615
* various fixes for mt7615
* unify some code between mt7603 and mt7615
* fix locking issues on mt76x02
* add support for toggling edcca on mt7603
* fix reading target tx power with ext PA on mt7603/mt7615
* fix initalizing channel maximum power
* fix rate control / tx status reporting issues on mt76x02/mt7603
* add support for eeprom calibration data from mtd on mt7615
* support configuring tx power on mt7615
* fix external PA support on mt76x0
* per-chain signal reporting on mt7615
* rx/tx buffer fixes for USB devices