mt76: update to the latest version

20c0766 mt7603: adjust rx hang watchdog for MT7628
664e321 mt7603: add extra PSE hang check signature for MT7628
f24b56f update MT7628 firmware to the latest version
d87e4b0 mt7603: clear PSE reset bit if PSE reset fails
0ef26ef mt76: only stop tx queues on offchannel, not during the entire scan
f399da3 mt76: prevent tx scheduling during channel change
21c1e1e mt76: move ieee80211_hw allocation to common core
730c292 mt76: wait for pending tx to complete before switching channel
fcbb49e mt76x2: use udelay instead of usleep_range in mt76x2_mac_stop
792dbe0 mt7603: do not hold dev->mutex while flushing dev->mac_work

Signed-off-by: Felix Fietkau <nbd@nbd.name>

package/kernel/mt76/Makefile

@@ -8,9 +8,9 @@ PKG_LICENSE_FILES:=
 
 PKG_SOURCE_URL:=https://github.com/openwrt/mt76
 PKG_SOURCE_PROTO:=git
-PKG_SOURCE_DATE:=2018-05-18
-PKG_SOURCE_VERSION:=0b8d1ddec926bf212f6d665d2dcfb0effd1b3c66
-PKG_MIRROR_HASH:=05cbccc8d7c1e7c3ceb95c8446ea1bda52353ff49df0e9cac8d9a8b40058622f
+PKG_SOURCE_DATE:=2018-05-20
+PKG_SOURCE_VERSION:=792dbe02613299f67e92815f0b2b7584dc951ffd
+PKG_MIRROR_HASH:=8b5747b868fc2af5b75c2d1aa289a165bf70732aae049907a3b82ca3c81f5480
 
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
 PKG_BUILD_PARALLEL:=1