Move OPENSSL_NO_RIPEMD160 to compat.

Move OPENSSL_NO_RIPEMD160 to compat and add ifdefs to mac.c around the
ripemd160 MACs.
diff --git a/digest-openssl.c b/digest-openssl.c
index 517d2a2..13b63c2 100644
--- a/digest-openssl.c
+++ b/digest-openssl.c
@@ -32,8 +32,7 @@
 #include "digest.h"
 #include "ssherr.h"
 
-#if !defined(HAVE_EVP_RIPEMD160) || defined(OPENSSL_NO_RIPEMD) || \
-    defined(OPENSSL_NO_RMD160)
+#ifndef HAVE_EVP_RIPEMD160
 # define EVP_ripemd160 NULL
 #endif /* HAVE_EVP_RIPEMD160 */
 #ifndef HAVE_EVP_SHA256