clearfog: Reduce image size so that it fits the eMMC

Yup, a classic error when it comes to sizes:

  mmcblk0: p4 size 4096000 extends beyond EOD, truncated

These are the actual sizes as reported by Linux on a booted system.
There are also two boot partitions, `boot0` and `boot1`.

 - mmcblk0: 15269888
 - boot0: 8192
 - boot1: 8192
 - p1: 4093952
 - p2: 4096000
 - p3: 4093952
 - p4: 2981888

This means that the total usable size on the "8GB eMMC", out-of-box,
is 7.28125 GiB. That's 3727 MB for each slot (two 1MB chunks are
reserved for the U-Boot when on SD-card for symmetry).

Change-Id: I08e35d9a95449dc779883d692c60e129a91a045b
diff --git a/board/czechlight/clearfog/genimage.cfg b/board/czechlight/clearfog/genimage.cfg
index 7633c8f..9bb6006 100644
--- a/board/czechlight/clearfog/genimage.cfg
+++ b/board/czechlight/clearfog/genimage.cfg
@@ -12,27 +12,27 @@
 		partition-type = 0x83
 		image = "rootfs.ext4"
 		offset = 1M
-		size = 1999M
+		size = 1863M
 	}
 
 	partition cfg-A {
 		partition-type = 0x83
 		image = "cfg.ext4"
-		offset = 2000M
-		size = 2000M
+		offset = 1864M
+		size = 1864M
 	}
 
 	partition rootfs-B {
 		partition-type = 0x83
 		image = "rootfs.ext4"
-		offset = 4001M
-		size = 1999M
+		offset = 3729M
+		size = 1863M
 	}
 
 	partition cfg-B {
 		partition-type = 0x83
 		image = "cfg.ext4"
-		offset = 6000M
-		size = 2000M
+		offset = 5592M
+		size = 1864M
 	}
 }