MAINTAINERS: ARM: vt8500: add Alexey and Krzysztof as maintainers

The ARM VIA/WonderMedia VT8500 platform became orphaned in
commit 8f1b7ba5

 ("MAINTAINERS: ARM/VT8500, remove defunct e-mail")
and clearly it is on the way out of the kernel.  However few folks send
patches to it and it is nice to actually take them, till the platform is
in the kernel.

Alexey Charkov still has VT8500 hardware and plans to work on upstream,
so add Alexey as the maintainer.  Krzysztof will collect patches.

Extend the maintainer entry to cover also VT8500 DTS.

Cc: Alexey Charkov <alchark@gmail.com>
Acked-by: Alexey Charkov <alchark@gmail.com>
Link: https://lore.kernel.org/r/20240613064612.8589-1-krzysztof.kozlowski@linaro.org


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>