x86: configurable DMI scanning code

Turn CONFIG_DMI into a selectable option if EMBEDDED is defined, in
order to be able to remove the DMI table scanning code if it's not
needed, and then reduce the kernel code size.

With CONFIG_DMI (i.e before) :

   text    data     bss     dec     hex filename
1076076  128656   98304 1303036  13e1fc vmlinux

Without CONFIG_DMI (i.e after) :

   text    data     bss     dec     hex filename
1068092  126308   98304 1292704  13b9a0 vmlinux

Result:

   text    data     bss     dec     hex filename
  -7984   -2348       0  -10332   -285c vmlinux

The new option appears in "Processor type and features", only when
CONFIG_EMBEDDED is defined.

This patch is part of the Linux Tiny project, and is based on previous work
done by Matt Mackall <mpm@selenic.com>.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Anvin" <hpa@zytor.com>
Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/dmi.h b/include/linux/dmi.h
index 325acdf..2a063b6 100644
--- a/include/linux/dmi.h
+++ b/include/linux/dmi.h
@@ -90,6 +90,7 @@
 static inline const char * dmi_get_system_info(int field) { return NULL; }
 static inline const struct dmi_device * dmi_find_device(int type, const char *name,
 	const struct dmi_device *from) { return NULL; }
+static inline void dmi_scan_machine(void) { return; }
 static inline int dmi_get_year(int year) { return 0; }
 static inline int dmi_name_in_vendors(const char *s) { return 0; }
 #define dmi_available 0