I recently upgraded uboot after upgrading manjaro and it suggesting a uboot upgrade. I am now unable to boot to my Kali SD card image as I could previously.
This is unfortunately very common. Hopefully your Manjaru doesn't quit working, preventing you from booting at all.
The solution is to install a different U-Boot, or Tow-Boot.
You could check /var/cache/pacman/pkg/uboot* for the previous version
You can also freely download the U-Boot manual and customize yours. I'm using U-Boot for the PBP (Kali), Tow Boot on the PP (Mobian, had to switch for an update) and haven't had to change anything on the PT2.
PinePhone, Pinebook Pro & PineTab2 owner.