sh: Add fixed ioremap support

Some devices need to be ioremap'd and accessed very early in the boot
process. It is not possible to use the standard ioremap() function in
this case because that requires kmalloc()'ing some virtual address space
and kmalloc() may not be available so early in boot.

This patch provides fixmap mappings that allow physical address ranges
to be remapped into the kernel address space during the early boot
stages.

Signed-off-by: Matt Fleming <matt@console-pimps.org>

arch/sh/kernel/setup.c

@@ -449,14 +449,15 @@ void __init setup_arch(char **cmdline_p)
 #ifdef CONFIG_DUMMY_CONSOLE
 	conswitchp = &dummy_con;
 #endif
+	paging_init();
+	pmb_init();
+
+	ioremap_fixed_init();
 
 	/* Perform the machine specific initialisation */
 	if (likely(sh_mv.mv_setup))
 		sh_mv.mv_setup(cmdline_p);
 
-	paging_init();
-	pmb_init();
-
 #ifdef CONFIG_SMP
 	plat_smp_setup();
 #endif