Add a Git tree on @kernel.org for maintaining the Samsung pinctrl
drivers.  The tree will be maintained in a shared model between current
Samsung pinctrl maintainers.  Pull requests will be going to Linus
Walleij.

Also add the patchwork for linux-samsung-soc mailing list which will be
used for handling the patches.
Signed-off-by: NKrzysztof Kozlowski <krzk@kernel.org>
Acked-by: NTomasz Figa <tomasz.figa@gmail.com>
Acked-by: NSylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>