linux-firmware: update firmware for MT7921 WiFi device

Update binary firmware for MT7921 WiFi devices

File: mediatek/WIFI_MT7961_patch_mcu_1_2_hdr.bin
Version: 20210519202729a
File: mediatek/WIFI_RAM_CODE_MT7961_1.bin
Version: 20210519202807
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Signed-off-by: Josh Boyer <jwboyer@kernel.org>

WHENCE

@@ -5017,9 +5017,9 @@ Licence: Redistributable. See LICENCE.mediatek for details.
 Driver: mt7921 - MediaTek MT7921 Wireless MACs
 
 File: mediatek/WIFI_MT7961_patch_mcu_1_2_hdr.bin
-Version: 20210122002654a
+Version: 20210519202729a
 File: mediatek/WIFI_RAM_CODE_MT7961_1.bin
-Version: 20210122002730
+Version: 20210519202807
 
 Licence: Redistributable. See LICENCE.mediatek for details.