UBUNTU: SAUCE: arm64: no osb() implementation yet

CVE-2017-5753 (Spectre v1 Intel)
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/arm64/include/asm/barrier.h

@@ -31,6 +31,8 @@
 #define mb()		dsb(sy)
 #define rmb()		dsb(ld)
 #define wmb()		dsb(st)
+#define osb()   	do { } while (0)
+#define osb_is_enabled	(0)
 
 #define dma_rmb()	dmb(oshld)
 #define dma_wmb()	dmb(oshst)