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

MAINTAINERS

@@ -13861,7 +13861,7 @@ T:	git https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux.git/
 F:	drivers/soc/microchip/
 
 MICROCHIP SPI DRIVER
-M:	Tudor Ambarus <tudor.ambarus@linaro.org>
+M:	Ryan Wanner <ryan.wanner@microchip.com>
 S:	Supported
 F:	drivers/spi/spi-atmel.*