MAINTAINERS: thermal: samsung: Drop obsolete properties

Update the Samsung Exynos SoC thermal driver entry to match reality and
add Krzysztof Kozlowski as co-maintainer (as he maintains entire Samsung
SoC).  The rationale:
1. Bartlomiej's Samsung email bounces, since he is not working in
   Samsung for some time.
2. The mentioned Lukasz Majewski's Git tree was not updated
   since 2015.

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Link: https://lore.kernel.org/r/20220122132554.65192-3-krzysztof.kozlowski@canonical.com


Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>