Coretex-M4 Comport

[katsu]

UART4 is changed to UART3 in the sample code of [EVK-MIMX8MM-hello_world].
Changes have been made based on the following.

Verdin IMX8MM, hardfault when initializing UART on M4 core

@hfranco.tx @rudhi.tx Sorry for the long wait for the reply back. I had a week and a half vacation planned and couldn’t get back to you. We checked the “verdin-imx8mm_hmp_overlay.dts”, this is not in our project but we do have the following file: verdin-imx8mm_rpmsg.dts (1.3 KB) This file looks exactly the same as the one mentioned. The code we used is: iuart_interrupt_transfer.zip (762.4 KB) We made changes to the board.c, the main file and the pinmux.c file to use UART2 instead of UART…