Fix the boot commands for Amd64 bootloader

Use correct boot commands for Amd64 since they are used
in all AUM tests during reboot.

Signed-off-by: Denis Pynkin <denis.pynkin@collabora.com>

templates/profiles.yaml

@@ -10,7 +10,9 @@ main-profile:
     baseurl: "https://images.apertis.org"
     boot_method: grub
     boot_commands:
-      - ramdisk
+      - set root='(hd0,gpt1)'
+      - chainloader /efi/boot/bootx64.efi
+      - boot
     needs_dtb: false
     dtb_root: ""
     device_type: minnowboard-turbot-E3826