errno.h: sync error macros with linux 4.8-rc7

For synchronization, import macros from
- include/uapi/asm-generic/errno-base.h
- include/uapi/asm-generic/errno.h
- include/linux/errno.h

of Linux 4.8-rc7.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Move ENOTSUPP defines to include/linux/errno.h

Collect a couple of duplicated defines into a single place.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Move error macros from <asm-generic/errno.h> to <linux/errno.h>

There are no files that include <asm-generic/errno.h> any more.
Move error macro defines to include/linux/errno.h and remove
include/asm-generic/errno.h.

Going forward, please include <linux/errno.h> when you need error
macros.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

Add <linux/errno.h> as a wrapper of <asm-generic/errno.h>

This will be used to consolidate errno.h variants.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Simon Glass <sjg@chromium.org>