Revert "batman-adv: drop dependency against CRC16"

This reverts commit 12afc36e.

The dependency is actually still necessary.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/batman-adv/Kconfig

@@ -5,6 +5,7 @@
 config BATMAN_ADV
 	tristate "B.A.T.M.A.N. Advanced Meshing Protocol"
 	depends on NET
+	select CRC16
 	select LIBCRC32C
         default n
 	help