m68k: define PAGE_OFFSET_RAW for ColdFire CPU with MMU enabled

The ColdFire CPU configurations need PAGE_OFFSET_RAW set to the base of
their RAM. It doesn't matter if they are running with the MMU enabled or
disabled, it is always set to the base of RAM.

We can keep the choices simple here and key of CONFIG_RAMBASE. If it is
defined we are on a plaftorm (ColdFire or other non-MMU systems) which
have a configurable RAM base, just use it.
Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Acked-by: Matt Waddel <mwaddel@yahoo.com>
Acked-by: Kurt Mahan <kmahan@xmission.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/page_offset.h

 /* This handles the memory map.. */
 
-#ifdef CONFIG_MMU
-#ifndef CONFIG_SUN3
-#define PAGE_OFFSET_RAW		0x00000000
-#else
+#if defined(CONFIG_RAMBASE)
+#define PAGE_OFFSET_RAW		CONFIG_RAMBASE
+#elif defined(CONFIG_SUN3)
 #define PAGE_OFFSET_RAW		0x0E000000
-#endif
 #else
-#define	PAGE_OFFSET_RAW		CONFIG_RAMBASE
+#define PAGE_OFFSET_RAW		0x00000000
 #endif