Revert "arm64: ioremap: add ioremap_cache macro"

This reverts commit 1b6d7f87.

This patch would conflict with Dan Williams' "tree-wide convert to
memremap()" series (ioremap_cache replaced by arch_memremap)
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/io.h

@@ -172,7 +172,6 @@ extern void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size);
 #define ioremap_wc(addr, size)		__ioremap((addr), (size), __pgprot(PROT_NORMAL_NC))
 #define ioremap_wt(addr, size)		__ioremap((addr), (size), __pgprot(PROT_DEVICE_nGnRE))
 #define iounmap				__iounmap
-#define ioremap_cache                  ioremap_cache
 
 /*
  * io{read,write}{16,32}be() macros