Copy dtb files to miniroots and install disk. Increase the ramdisk size

and force long filenames on the first mount of fat 16 filesystems so
this works.
U-boot scripts have not yet been changed to load these files.
ok kettenis@

src/etc/etc.armv7/disktab

@@ -1,10 +1,10 @@
-# $OpenBSD: disktab,v 1.4 2015/08/14 23:45:55 krw Exp $
+# $OpenBSD: disktab,v 1.5 2016/05/21 07:19:24 jsg Exp $
 
 # Leave nc=16; adjust size using: ns
 rdroot|ramdiskroot|RAM-disk root FS image:\
-	:dt=rdroot:se#512:nc#16:nt#2:ns#320:\
-	:ta=4.2BSD:oa#0:pa#10240:fa#512:ba#4096:\
-	:ob#0:pb#0:oc#0:pc#10240:
+	:dt=rdroot:se#512:nc#16:nt#2:ns#480:\
+	:ta=4.2BSD:oa#0:pa#15360:fa#512:ba#4096:\
+	:ob#0:pb#0:oc#0:pc#15360:
 
 
 rdroot2.5M|ramdiskroot2.5M|RAM-disk root FS image:\