arm64/xen: implement ioremap_cached on arm64

Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>

arch/arm64/include/asm/io.h

@@ -228,10 +228,12 @@ extern void __iounmap(volatile void __iomem *addr);
 #define PROT_DEFAULT		(PTE_TYPE_PAGE | PTE_AF | PTE_DIRTY)
 #define PROT_DEVICE_nGnRE	(PROT_DEFAULT | PTE_PXN | PTE_UXN | PTE_ATTRINDX(MT_DEVICE_nGnRE))
 #define PROT_NORMAL_NC		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL_NC))
+#define PROT_NORMAL		(PROT_DEFAULT | PTE_ATTRINDX(MT_NORMAL))
 
 #define ioremap(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
 #define ioremap_nocache(addr, size)	__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
 #define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
+#define ioremap_cached(addr, size)	__ioremap((addr), (size), __pgprot(PROT_NORMAL))
 #define iounmap				__iounmap
 
 #define PROT_SECT_DEFAULT	(PMD_TYPE_SECT | PMD_SECT_AF)