rauc: Do not require an extra partition

...because we can do better by patching the built-in U-Boot's
configuration. Yup, it's a patch that is going to be quite painful to
maintain, but on the other hand the whole idea here is to *not* touch
the bootloader anyway because that is a risky operation. For that, it's
arguably safer to not rely on yet another piece of configuration (the
boot script) for reliable operation.

Change-Id: Ie559cf07d1dc6e50bc6ff80320509e3933b0af93
diff --git a/board/czechlight/clearfog/overlay/etc/rauc/system.conf b/board/czechlight/clearfog/overlay/etc/rauc/system.conf
index 40b839e..8de0da8 100644
--- a/board/czechlight/clearfog/overlay/etc/rauc/system.conf
+++ b/board/czechlight/clearfog/overlay/etc/rauc/system.conf
@@ -3,9 +3,9 @@
 bootloader=uboot
 
 [slot.rootfs.0]
-device=/dev/mmcblk0p2
+device=/dev/mmcblk0p1
 bootname=A
 
 [slot.rootfs.1]
-device=/dev/mmcblk0p3
+device=/dev/mmcblk0p2
 bootname=B