CM4_1 core will use the UART2 on QM MEK base board as its console. Since this port currently
is a backup debug port on A core side, not really used. We disable it in dts to yield the port
for CM4_1.
Signed-off-by: Ye Li <ye.li@nxp.com> Acked-by: Fugang Duan <fugang.duan@nxp.com>