Add an empty u-boot environment to mx6qsabrelite images

The Apertis update manager needs a valid u-boot environment to handle
the rollback. Do it an image generation so that every image
distributed already have a valid env.

Signed-off-by: Frédéric Dalleau <frederic.dalleau@collabora.com>

apertis-image-mx6qsabrelite.yaml

@@ -100,6 +100,17 @@ actions:
     source: /usr/lib/u-boot/mx6qsabrelite/u-boot.imx
     offset: {{ sector 2 }}
 
+  - action: run
+    description: Create defaut environment for u-boot
+    chroot: false
+    command: echo "bootcount=0" > u-boot.env ; mkenvimage -s 0x2000 -o u-boot.env u-boot-env.txt
+
+  - action: raw
+    description: Install U-Boot environment
+    origin: filesystem
+    source: u-boot.env
+    offset: 0xC0000
+
   - action: run
     description: "Save installed package status"
     chroot: false