mt76: update to the latest version

73301065ac32 mt76: mt7615: reduce maximum VHT MPDU length to 7991
8c47ed12c2be mt76: mt7915: add offchannel condition in switch channel command
1449e602fa10 mt76: Convert to DEFINE_SHOW_ATTRIBUTE
b22977c2727d mt76: mt7663s: remove max_tx_fragments limitation

Signed-off-by: Felix Fietkau <[email protected]>

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:=2020-09-18
-PKG_SOURCE_VERSION:=ec84891a4d23efcab2ea91980c4933601cb017bd
-PKG_MIRROR_HASH:=55c4103d1d1a62c7401ad0e163773b209c63335a133fd9dd3bcd06e5ada93c1b
+PKG_SOURCE_DATE:=2020-09-23
+PKG_SOURCE_VERSION:=b22977c2727db7fea8d487573edb3aa668d8309d
+PKG_MIRROR_HASH:=4182823ec5a97d842e7404b3c8139de8af4f35948008890d50e4dad95add996b
 
 PKG_MAINTAINER:=Felix Fietkau <[email protected]>
 PKG_BUILD_PARALLEL:=1