scripts/checkpatch.pl: reset rpt_cleaners warnings ...

When running checkpatch against multiple patches and one
of them has a whitespace issue, all following patches will
contain the same note, even if they are ok.

This patch is taken from the linux kernel:

scripts/checkpatch.pl: reset rpt_cleaners warnings
b078121
Written by Mike Frysinger <vapier@gentoo.org>

Signed-off-by: Teresa Gámez <t.gamez@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: Adapt checkpatch.pl for barebox. ...

Add directories from root of barebox to top_of_kernel_tree()
function for usage of script without additional parameters.

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

scripts: Add checkpatch.pl script. ...

Overtake script checkpatch.pl from kernel source.

Signed-off-by: Marek Belisko <marek.belisko@open-nandra.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>