Add 64-bit rotates

src/include/gpxe/bitops.h

         return ( ( data >> rotation ) | ( data << ( 32 - rotation ) ) );
 }
 
+static inline uint64_t rol64 ( uint64_t data, unsigned int rotation ) {
+        return ( ( data << rotation ) | ( data >> ( 64 - rotation ) ) );
+}
+
+static inline uint64_t ror64 ( uint64_t data, unsigned int rotation ) {
+        return ( ( data >> rotation ) | ( data << ( 64 - rotation ) ) );
+}
+
 #endif /* _GPXE_BITOPS_H */