MAINTAINERS: add myself as maintainer for mcp16502

Andrei is no longer with Microchip. Add myself as maintainer for
MCP16502. Along with this change the status from maintained to
supported.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Link: https://lore.kernel.org/r/1610028927-9842-4-git-send-email-claudiu.beznea@microchip.com


Signed-off-by: Mark Brown <broonie@kernel.org>