set dt=floppy for floppy labels

src/etc/etc.i386/disktab

@@ -73,13 +73,13 @@ cp3100new|Conner Peripherals 100MB IDE, with a different configuration:\
 	:ph#130416:oh#71808:th=4.2BSD:bh#4096:fh#512:
 
 floppy|floppy3|3in|3.5in High Density Floppy:\
-	:ty=floppy:se#512:nt#2:rm#300:ns#18:nc#80:\
+	:dt=floppy:ty=floppy:se#512:nt#2:rm#300:ns#18:nc#80:\
 	:pa#2880:oa#0:ba#4096:fa#512:ta=4.2BSD:ba#4096:fa#512: \
 	:pb#2880:ob#0:\
 	:pc#2880:oc#0:
 
 floppy5|5in|5.25in High Density Floppy:\
-	:ty=floppy:se#512:nt#2:rm#300:ns#15:nc#80:\
+	:dt=floppy:ty=floppy:se#512:nt#2:rm#300:ns#15:nc#80:\
 	:pa#2400:oa#0:ba#4096:fa#512:ta=4.2BSD:ba#4096:fa#512:\
 	:pb#2400:ob#0:bb#4096:fb#512:\
 	:pc#2400:oc#0:bc#4096:fc#512: