MAINTAINERS: update entry for Microchip NAND driver support

Replace the Microchip/Atmel NAND controller driver maintainer
by removing Josh and adding Tudor.

Cc: Josh Wu <rainyfeeling@outlook.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

MAINTAINERS

@@ -9528,7 +9528,7 @@ F:	drivers/media/platform/atmel/atmel-isc-regs.h
 F:	devicetree/bindings/media/atmel-isc.txt
 
 MICROCHIP / ATMEL NAND DRIVER
-M:	Josh Wu <rainyfeeling@outlook.com>
+M:	Tudor Ambarus <tudor.ambarus@microchip.com>
 L:	linux-mtd@lists.infradead.org
 S:	Supported
 F:	drivers/mtd/nand/raw/atmel/*