crypto: ccp - Make ccp_register_rsa_alg static

Fix sparse warning:

drivers/crypto/ccp/ccp-crypto-rsa.c:251:5:
 warning: symbol 'ccp_register_rsa_alg' was not declared. Should it be static?
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Acked-by: Gary R Hook <gary.hook@amd.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

drivers/crypto/ccp/ccp-crypto-rsa.c

@@ -248,7 +248,8 @@ static struct ccp_rsa_def rsa_algs[] = {
 	}
 };
 
-int ccp_register_rsa_alg(struct list_head *head, const struct ccp_rsa_def *def)
+static int ccp_register_rsa_alg(struct list_head *head,
+			        const struct ccp_rsa_def *def)
 {
 	struct ccp_crypto_akcipher_alg *ccp_alg;
 	struct akcipher_alg *alg;