Bring sdata back into use.

Assuming the push I just fixed works, it should now be safe to bring
sdata back into the standard configuration.

Signed-off-by: Ronald G. Minnich <rminnich@gmail.com>

sys/src/9/amd64/build.json

@@ -70,6 +70,7 @@
 					"usbehci"
 				],
 				"Sd": [
+					"sdata",
 					"sdiahci"
 				],
 				"Uart": [