mtd: resync with Linux-3.7.1

This patch is essentially an update of u-boot MTD subsystem to
the state of Linux-3.7.1 with exclusion of some bits:

- the update is concentrated on NAND, no onenand or CFI/NOR/SPI
flashes interfaces are updated EXCEPT for API changes.

- new large NAND chips support is there, though some updates
have got in Linux-3.8.-rc1, (which will follow on top of this patch).

To produce this update I used tag v3.7.1 of linux-stable repository.

The update was made using application of relevant patches,
with changes relevant to U-Boot-only stuff sticked together
to keep bisectability. Then all changes were grouped together
to this patch.

Signed-off-by: Sergey Lapin <slapin@ossfans.org>
[scottwood@freescale.com: some eccstrength and build fixes]
Signed-off-by: Scott Wood <scottwood@freescale.com>

include/linux/string.h

@@ -85,6 +85,9 @@ extern int memcmp(const void *,const void *,__kernel_size_t);
 #ifndef __HAVE_ARCH_MEMCHR
 extern void * memchr(const void *,int,__kernel_size_t);
 #endif
+#ifndef __HAVE_ARCH_MEMCHR_INV
+void *memchr_inv(const void *, int, size_t);
+#endif
 
 #ifdef __cplusplus
 }