crypto/caam: Export gen_split_key symbol for other modules

In 3.6-rc3, without this patch, the following error occurs with a modular build:

ERROR: "gen_split_key" [drivers/crypto/caam/caamhash.ko] undefined!
ERROR: "gen_split_key" [drivers/crypto/caam/caamalg.ko] undefined!
Signed-off-by: NBen Collins <ben.c@servergy.com>
Cc: Yuan Kang <Yuan.Kang@freescale.com>
Acked-by: NKim Phillips <kim.phillips@freescale.com>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/key_gen.c

@@ -120,3 +120,4 @@ u32 gen_split_key(struct device *jrdev, u8 *key_out, int split_key_len,
 
 	return ret;
 }
+EXPORT_SYMBOL(gen_split_key);