backport patch to populate /proc/device-tree/chosen/u-boot,version

This is in upstream u-boot as:

commit 622ecee93a604c017aca23906c5cc903b4002b78 Author: Francesco Dolcini francesco.dolcini@toradex.com Date: Thu May 19 16:22:26 2022 +0200

fdt: Add U-Boot version to chosen node

Add a new device tree property "u-boot,version" in the chosen node to
pass the U-Boot version to the operating system.
This can be useful to implement a firmware upgrade procedure from the
operating system.

Signed-off-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

The version now looks like this (with a local fake 2025-11-24 git tag):

2022.04 MNT Reform 2 with i.MX8MP Module 2025-11-24-gb0e908b1-dirty