Avoid redefinition of be32enc() on NetBSD.

src/libsodium/crypto_pwhash/scryptsalsa208sha256/pbkdf2-sha256.c

@@ -32,19 +32,9 @@
 
 #include "crypto_auth_hmacsha256.h"
 #include "pbkdf2-sha256.h"
+#include "sysendian.h"
 #include "utils.h"
 
-static inline void
-be32enc(void *pp, uint32_t x)
-{
-    uint8_t * p = (uint8_t *)pp;
-
-    p[3] = x & 0xff;
-    p[2] = (x >> 8) & 0xff;
-    p[1] = (x >> 16) & 0xff;
-    p[0] = (x >> 24) & 0xff;
-}
-
 /**
  * PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, c, buf, dkLen):
  * Compute PBKDF2(passwd, salt, c, dkLen) using HMAC-SHA256 as the PRF, and