Update MTD to that of Linux 2.6.22.1

A lot changed in the Linux MTD code, since it was last ported from
Linux to U-Boot. This patch takes U-Boot NAND support to the level
of Linux 2.6.22.1 and will enable support for very large NAND devices
(4KB pages) and ease the compatibility between U-Boot and Linux
filesystems.

This patch is tested on two custom boards with PPC and ARM
processors running YAFFS in U-Boot and Linux using gcc-4.1.2
cross compilers.

MAKEALL ppc/arm has some issues:
 * DOC/OneNand/nand_spl is not building (I have not tried porting
   these parts, and since I do not have any HW and I am not familiar
   with this code/HW I think its best left to someone else.)

Except for the issues mentioned above, I have ported all drivers
necessary to run MAKEALL ppc/arm without errors and warnings. Many
drivers were trivial to port, but some were not so trivial. The
following drivers must be examined carefully and maybe rewritten to
some degree:
 cpu/ppc4xx/ndfc.c
 cpu/arm926ejs/davinci/nand.c
 board/delta/nand.c
 board/zylonite/nand.c

Signed-off-by: William Juul <william.juul@tandberg.com>
Signed-off-by: Stig Olsen <stig.olsen@tandberg.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>

include/linux/mtd/jffs2-user.h

@@ -0,0 +1,35 @@
+/*
+ * $Id: jffs2-user.h,v 1.1 2004/05/05 11:57:54 dwmw2 Exp $
+ *
+ * JFFS2 definitions for use in user space only
+ */
+
+#ifndef __JFFS2_USER_H__
+#define __JFFS2_USER_H__
+
+/* This file is blessed for inclusion by userspace */
+#include <linux/jffs2.h>
+#include <endian.h>
+#include <byteswap.h>
+
+#undef cpu_to_je16
+#undef cpu_to_je32
+#undef cpu_to_jemode
+#undef je16_to_cpu
+#undef je32_to_cpu
+#undef jemode_to_cpu
+
+extern int target_endian;
+
+#define t16(x) ({ uint16_t __b = (x); (target_endian==__BYTE_ORDER)?__b:bswap_16(__b); })
+#define t32(x) ({ uint32_t __b = (x); (target_endian==__BYTE_ORDER)?__b:bswap_32(__b); })
+
+#define cpu_to_je16(x) ((jint16_t){t16(x)})
+#define cpu_to_je32(x) ((jint32_t){t32(x)})
+#define cpu_to_jemode(x) ((jmode_t){t32(x)})
+
+#define je16_to_cpu(x) (t16((x).v16))
+#define je32_to_cpu(x) (t32((x).v32))
+#define jemode_to_cpu(x) (t32((x).m))
+
+#endif /* __JFFS2_USER_H__ */