crypto: user - Depend on NET instead of selecting it

Selecting NET causes all sorts of issues, including a dependency
loop involving bluetooth.  This patch makes it a dependency instead.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/crypto/Kconfig b/crypto/Kconfig
index 259dea9..527a857 100644
--- a/crypto/Kconfig
+++ b/crypto/Kconfig
@@ -102,8 +102,8 @@
 
 config CRYPTO_USER
 	tristate "Userspace cryptographic algorithm configuration"
+	depends on NET
 	select CRYPTO_MANAGER
-	select NET
 	help
 	  Userapace configuration for cryptographic instantiations such as
 	  cbc(aes).