crypto: caam - consolidate split key length computation

Move split key length and padded length computation from caamalg.c
and caamhash.c to key_gen.c.

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/key_gen.h

@@ -13,4 +13,5 @@ struct split_key_result {
 void split_key_done(struct device *dev, u32 *desc, u32 err, void *context);
 
 int gen_split_key(struct device *jrdev, u8 *key_out,
-		  struct alginfo * const adata, const u8 *key_in, u32 keylen);
+		  struct alginfo * const adata, const u8 *key_in, u32 keylen,
+		  int max_keylen);