MAINTAINERS: Add myself as a maintainer for Microchip SPI

Tudor is not with Microchip anymore. I have worked lately
with Microchip SPI drivers replacing Tudor with myself as this
maintainer.

Signed-off-by: Ryan Wanner <Ryan.Wanner@microchip.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Acked-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Link: https://lore.kernel.org/r/20230630161700.448747-1-Ryan.Wanner@microchip.com


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