powerpc: Add a checkpatch wrapper with our preferred settings

[Michael Ellerman]

On Tue, 2018-07-24 at 14:03:46 UTC, Michael Ellerman wrote:
> This makes it easy to run checkpatch with settings that we have agreed
> on (bwhahahahah).
> 
> Usage is eg:
> 
>   $ ./arch/powerpc/tools/checkpatch.sh -g origin/master..
> 
> To check all commits since origin/master.
> 
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> Reviewed-by: Russell Currey <ruscur at russell.cc>

Applied to powerpc next.

https://git.kernel.org/powerpc/c/7cd129b4b5370030a5c0b8031a54b2

cheers