[MIPS] fixmap: delete unused __set_fixmap, set_fixmap and set_fixmap_nocache

Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

include/asm-mips/fixmap.h

@@ -60,16 +60,6 @@ enum fixed_addresses {
 	__end_of_fixed_addresses
 };
 
-extern void __set_fixmap(enum fixed_addresses idx,
-			 unsigned long phys, pgprot_t flags);
-
-#define set_fixmap(idx, phys) \
-		__set_fixmap(idx, phys, PAGE_KERNEL)
-/*
- * Some hardware wants to get fixmapped without caching.
- */
-#define set_fixmap_nocache(idx, phys) \
-		__set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE)
 /*
  * used by vmalloc.c.
  *