MIPS: barrier: Clean up sync_ginv()

Use the new __SYNC() infrastructure to implement sync_ginv(), for
consistency with much of the rest of the asm/barrier.h.
Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org
Cc: Huacai Chen <chenhc@lemote.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: linux-kernel@vger.kernel.org

arch/mips/include/asm/barrier.h

@@ -163,7 +163,7 @@ static inline void wmb(void)
 
 static inline void sync_ginv(void)
 {
-	asm volatile("sync\t%0" :: "i"(__SYNC_ginv));
+	asm volatile(__SYNC(ginv, always));
 }
 
 #include <asm-generic/barrier.h>