kconfig: include common Kconfig files from top-level Kconfig ...

Based on this linux kernel commit:

> commit 1572497
> Author: Christoph Hellwig <hch@lst.de>
> Date:   Tue Jul 31 13:39:30 2018 +0200
>
>     kconfig: include common Kconfig files from top-level Kconfig

Signed-off-by: Antony Pavlov <antonynpavlov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

sandbox: allow "make ARCH=sandbox allyesconfig" ...

Compiling the tree with allyesconfig is helpful because different
compilers (gcc, clang) or static checkers (e.g. clang's scan-build)
can then process and check more code.

This patch introduces two new configuration symbols that Kconfig files
can depend on. That way, code that is only working where a cache or DMA
implementation exists can be opted out.

Signed-off-by: Holger Schurig <holgerschurig@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

consistently use the same bitops.h file ...

We have many variants of the same bitops.h file. Consistently
use the same file for all architectures which completely use
the generic bitops versions.

Some architectures had static inline versions of functions
identically to the generic versions, these are removed and
the generic versions are used directly now.

Also several architectures depend on the generic find_*_bit
functions but didn't have the GENERIC_FIND_NEXT_BIT Kconfig
option selected. This is added where needed.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Set model and hostname at boardlevel ...

With multiboard support the compiletime generated BOARDINFO string
gets more and more meaningless. This removes it from Kconfig and
replaces it with a variable that can be set at boardlevel.

Also many boards have a standard setting for the hostname in the
environment. This patch also moves the standard to C code by calling
barebox_set_hostname().

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Cleanup Kconfig files ...

This patch provides a global cleanup barebox Kconfig files. This includes
replacing spaces to tabs, formatting in accordance format, removing
extraneous lines and spaces. No functional changes.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

move digest to crypto/ ...

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Add Nios2 arch support to barebox ...

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>