mt76: update to the latest version, fixes stability issues

8a649c3 mt7603: mac: code optimization
8dee788 mt7603: mac: stop netdev queues during watchdog reset
3c4c9a6 tx: move state check in mt76_txq_send_burst()

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:=2017-07-04
-PKG_SOURCE_VERSION:=e90a81a5523e567efb1fe33bac677cfac644101f
-PKG_MIRROR_HASH:=6c40885a4f29f6842b6426568ae7d4b6c3e91f4a510c475e8fecaec03ae5f2f2
+PKG_SOURCE_DATE:=2017-07-17
+PKG_SOURCE_VERSION:=3c4c9a647e4feff3a42ee94d477041fdcf26c463
+PKG_MIRROR_HASH:=7ed7ef6356fafc2525cb6204ca2a3d584c1b83340ef5a1f7c581052f3a1982b1
 
 PKG_MAINTAINER:=Felix Fietkau <nbd@nbd.name>
 PKG_BUILD_PARALLEL:=1