fix -T option for doctype

We used to set $dev to -T, and leave the device type
in the argument list. Now, we set it to -T$2, and shift
it out of the list.

rc/bin/doctype

@@ -13,7 +13,8 @@ while(~ $1 -*){
 		eqn=neqn
 		prefer='prefer -n'
 	case -T
-		dev=$1
+		dev=-T$2
+		shift
 	case -*
 		opt=$opt' $1'
 	}