set_memory.h: Provide set_memory_{en,de}crypted() stubs

... to make these APIs more universally available.
Tested-by: Tom Lendacky <thomas.lendacky@amd.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Jon Mason <jdmason@kudzu.us>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Muli Ben-Yehuda <mulix@mulix.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: iommu@lists.linux-foundation.org
Link: http://lkml.kernel.org/r/20180319103826.12853-11-hch@lst.deSigned-off-by: Ingo Molnar <mingo@kernel.org>

include/linux/set_memory.h

@@ -17,4 +17,16 @@ static inline int set_memory_x(unsigned long addr,  int numpages) { return 0; }
 static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
 #endif
 
+#ifndef CONFIG_ARCH_HAS_MEM_ENCRYPT
+static inline int set_memory_encrypted(unsigned long addr, int numpages)
+{
+	return 0;
+}
+
+static inline int set_memory_decrypted(unsigned long addr, int numpages)
+{
+	return 0;
+}
+#endif /* CONFIG_ARCH_HAS_MEM_ENCRYPT */
+
 #endif /* _LINUX_SET_MEMORY_H_ */