MAINTAINERS: Switch to kernel.org account for Krzysztof Kozlowski

Change my email address to kernel.org account instead of Samsung one.

Add Bartlomiej Zolnierkiewicz as a co-maintainer of Maxim and Samsung
PMIC drivers.  These are used on many of our boards along with Exynos
SoCs and Samsung R&D Institute Poland can still take care of them.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: linux-samsung-soc@vger.kernel.org
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Acked-by: Kukjin Kim <kgene@kernel.org>