mt76: update to the latest version

0b6c9a043f78 mt76: move de-amsdu buffer per-phy
48a905e23791 mt76: mt7615: fix CSA event format
fbef8bba038f mt76: mt7921: remove duplicated macros in mcu.h

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:=2021-03-15
-PKG_SOURCE_VERSION:=ca22cc221ae7c87535d6f24b12c0280f6b560b31
-PKG_MIRROR_HASH:=291f078568a83aa9e930e3d496a8b0e406feb720c472aafc82fefe01c921e04d
+PKG_SOURCE_DATE:=2021-03-18
+PKG_SOURCE_VERSION:=fbef8bba038f5aff755e383025f0a8b34879aa5c
+PKG_MIRROR_HASH:=987826653cd8722671263c218a9f3cdf5b0bc0e24accf66fe68e1138f9c694b2
 
 PKG_MAINTAINER:=Felix Fietkau <[email protected]>
 PKG_BUILD_PARALLEL:=1