Configure IO functions on revision B board to use I2S

We are developing our own carrier board for the Jetson Nano.
At this point I am using a B01 module from a development kit.

One of the features I need to test is I2S and I understood from the other forum posts that I need to recompile U-boot with the right device tree to get this working.

I tried following this manual:

After I flashed the board, it no longer boots. This is a part of the startup log.
Can somebody point me to where it went wrong?

Thanks!

U-Boot 2016.07 (Mar 11 2020 - 16:27:34 +0100)

TEGRA210
Model: NVIDIA P3450-Porg
Board: NVIDIA P3450-PORG
DRAM:  4 GiB
MMC:   Tegra SD/MMC: 0, Tegra SD/MMC: 1
SF: Detected MX25U3235F with page size 256 Bytes, erase size 4 KiB, total 4 MiB
*** Warning - bad CRC, using default environment

In:    serial
Out:   serial
Err:   serial
Can't find nvidia,ethernet-mac property in CBoot DTB
Net:   No ethernet found.
Hit any key to stop autoboot:  0
switch to partitions #0, OK
mmc1 is current device
Scanning mmc 1:1...
Card did not respond to voltage select!
starting USB...
USB0:   tegrausb: Invalid dr_mode 2 for host mode
probe failed, error -1
USB error: all controllers failed lowlevel init

Error: eth_rtl8169 address not set.

Hello!

Starting with L4T release 32.3.1 or JetPack 4.3, this document is now out-of-date and we are working to update our documentation. So apologies that this is not clear. From 32.3.1 now you only need to update the CBoot pinmux, so skip the section in the application note about updating the U-Boot pinmux.

Let me know if this helps.

Regards,
Jon