kas: corstone1000: set branches to mickledore

point poky/meta-openembedded to mickledore
Signed-off-by: Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

kas/corstone1000-base.yml

@@ -5,7 +5,7 @@ distro: poky-tiny
 
 defaults:
   repos:
-    refspec: master
+    refspec: mickledore
 
 repos:
   meta-arm: