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/genimage.cfg b/board/czechlight/clearfog/genimage.cfg
index 9ec9991..a0e0471 100644
--- a/board/czechlight/clearfog/genimage.cfg
+++ b/board/czechlight/clearfog/genimage.cfg
@@ -1,12 +1,3 @@
-image boot.vfat {
-	vfat {
-		files = {
-			"boot.scr",
-		}
-	}
-	size = 1M
-}
-
 image sdcard.img {
 	hdimage {
 	}
@@ -17,15 +8,10 @@
 		offset = 512
 	}
 
-	partition boot {
-		partition-type = 0xc
-		image = "boot.vfat"
-		offset = 1M
-	}
-
 	partition rootfs-A {
 		partition-type = 0x83
 		image = "rootfs.ext4"
+		offset = 1M
 	}
 
 	partition rootfs-B {