crypto/sm2/sm2_za.c: include internal/numbers.h

Needed for the platforms that don't define UINT16_MAX.
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6414)

crypto/sm2/sm2_za.c

@@ -15,6 +15,7 @@
 #include <openssl/evp.h>
 #include <openssl/bn.h>
 #include <string.h>
+#include "internal/numbers.h"
 
 int sm2_compute_userid_digest(uint8_t *out,
                               const EVP_MD *digest,