According to MediaTek MT7688 Datasheet v1.4, as well as the MT7628
counterpart, the memory controller reset bit (MC_RST) is 10, not 20.
Reset bit 20 is used for for UART 2 (UART2_RST).
Please note: Due to the lack of hardware, I was not able to test this
change.
Signed-off-by: Reto Schneider <reto.schneider@husqvarnagroup.com>