MAINTAINERS: Tomasz has moved

I am leaving Samsung, so my current e-mail address is not going to work
any longer. Replace it with my private one. In addition, Sylwester
Nawrocki is being added as co-maintainer for Samsung clock drivers to
take some of the responsibilities, as I will be doing my part in my spare
time.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>