firmware/dmi_scan: generalize for use by other archs

This patch makes a couple of changes to the SMBIOS/DMI scanning
code so it can be used on other archs (such as ARM and arm64):
(a) wrap the calls to ioremap()/iounmap(), this allows the use of a
    flavor of ioremap() more suitable for random unaligned access;
(b) allow the non-EFI fallback probe into hardcoded physical address
    0xF0000 to be disabled.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Grant Likely <grant.likely@linaro.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/x86/include/asm/dmi.h b/arch/x86/include/asm/dmi.h
index fd8f9e2..535192f 100644
--- a/arch/x86/include/asm/dmi.h
+++ b/arch/x86/include/asm/dmi.h
@@ -13,7 +13,9 @@
 }
 
 /* Use early IO mappings for DMI because it's initialized early */
-#define dmi_ioremap early_ioremap
-#define dmi_iounmap early_iounmap
+#define dmi_early_remap		early_ioremap
+#define dmi_early_unmap		early_iounmap
+#define dmi_remap		ioremap
+#define dmi_unmap		iounmap
 
 #endif /* _ASM_X86_DMI_H */