crypto: rsa - unimplement sign/verify for raw RSA backends

In preparation for new akcipher verify call remove sign/verify callbacks
from RSA backends and make PKCS1 driver call encrypt/decrypt instead.

This also complies with the well-known idea that raw RSA should never be
used for sign/verify. It only should be used with proper padding scheme
such as PKCS1 driver provides.

Cc: Giovanni Cabiddu <giovanni.cabiddu@intel.com>
Cc: qat-linux@intel.com
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Gary Hook <gary.hook@amd.com>
Cc: Horia Geantă <horia.geanta@nxp.com>
Cc: Aymen Sghaier <aymen.sghaier@nxp.com>
Signed-off-by: Vitaly Chikunov <vt@altlinux.org>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Acked-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/caam/caampkc.c

@@ -994,8 +994,6 @@ static void caam_rsa_exit_tfm(struct crypto_akcipher *tfm)
 static struct akcipher_alg caam_rsa = {
 	.encrypt = caam_rsa_enc,
 	.decrypt = caam_rsa_dec,
-	.sign = caam_rsa_dec,
-	.verify = caam_rsa_enc,
 	.set_pub_key = caam_rsa_set_pub_key,
 	.set_priv_key = caam_rsa_set_priv_key,
 	.max_size = caam_rsa_max_size,