microblaze: add a dummy pgprot_noncached

Some device drivers call this, so add a macro
that pretends to do this. Since there is no
MMU support, it won't actually result in an
uncached mapping, though.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/include/asm/pgtable.h

@@ -27,6 +27,8 @@
 #define PAGE_READONLY		__pgprot(0) /* these mean nothing to non MMU */
 #define PAGE_KERNEL		__pgprot(0) /* these mean nothing to non MMU */
 
+#define pgprot_noncached(x)	(x)
+
 #define __swp_type(x)		(0)
 #define __swp_offset(x)		(0)
 #define __swp_entry(typ, off)	((swp_entry_t) { ((typ) | ((off) << 7)) })