MAINTAINERS: pinctrl: Move Thomas Abraham to CREDITS

Thomas Abraham's Linaro email address bounces for several months. Also
there were no replies for several emails sent on LKML to his Samsung
address. Move his name to CREDITS.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: Tomasz Figa <tomasz.figa@gmail.com>
Cc: Thomas Abraham <thomas.ab@samsung.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Link: http://lkml.org/lkml/2015/6/15/15


Signed-off-by: Linus Walleij <linus.walleij@linaro.org>