im8mq start in uboot, m4 debug port output is normal
After kernel is started, the imx8mq and m4 send messages to each other through RPMSG is okay.
But M4 debug port output is garbled.
root@imx8mq:~# cat /proc/cmdline
console=ttymxc0,115200 earlycon=ec_imx6q,0x30860000,115200 root=/dev/mmcblk1p2 rootwait rw video=HDMI-A-1:1920x1080@60 uart_from_osc=1
