Adapt to new version of RPi4 U-boot

The U-boot version in LAVA for RPi4 has been updated to
2024.01+dfsg-1+apertis7bv2025dev3b1 which supports a new layout for RPi4
to allow larger kernels to be used.

The previous U-boot version in LAVA for RPi4 was
2021.10+dfsg-1+apertis10bv2022.1b3 which had different default environment,
witch supported distro_boot as command.

By default Apertis relied in distro_boot which was the standard way of
booting distributions in previous U-boot version. With the new version
U-boot the boot command needs to be adapted to use bootflow

https://docs.u-boot.org/en/stable/develop/bootstd.html



Signed-off-by: Walter Lozano <walter.lozano@collabora.com>

lava/devices.yaml

@@ -40,7 +40,7 @@ device-arm64-bcm2711-rpi-4-b:
       board: rpi64
       boot_method: u-boot
       boot_commands:
-        - if test ${bootcount} -lt ${bootlimit}; then run distro_bootcmd; else run altbootcmd; fi
+        - if test ${bootcount} -lt ${bootlimit}; then run bootcmd; else run altbootcmd; fi
       deploy_device: sd-card
       device_type: bcm2711-rpi-4-b
       firststagedtb: broadcom/bcm2711-rpi-4-b.dtb