crypto: picoxcell - add dependency on HAVE_CLK

The picoxcell crypto driver requires the clk API, but the platform in
mainline does not currently support it.  Add an explicit dependency on
HAVE_CLK to avoid build breakage.

Signed-off-by: Jamie Iles <jamie@jamieiles.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/drivers/crypto/Kconfig b/drivers/crypto/Kconfig
index e0b25de..4ac6d4d 100644
--- a/drivers/crypto/Kconfig
+++ b/drivers/crypto/Kconfig
@@ -266,7 +266,7 @@
 
 config CRYPTO_DEV_PICOXCELL
 	tristate "Support for picoXcell IPSEC and Layer2 crypto engines"
-	depends on ARCH_PICOXCELL
+	depends on ARCH_PICOXCELL && HAVE_CLK
 	select CRYPTO_AES
 	select CRYPTO_AUTHENC
 	select CRYPTO_ALGAPI