arm64: Implement ioremap_np() to map MMIO as nGnRnE

This is used on Apple ARM platforms, which require most MMIO
(except PCI devices) to be mapped as nGnRnE.
Acked-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Hector Martin <marcan@marcan.st>

arch/arm64/include/asm/io.h

@@ -169,6 +169,7 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 
 #define ioremap(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
 #define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
+#define ioremap_np(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRnE))
 
 /*
  * PCI configuration space mapping function.