MAINTAINERS: normalize Woojung Huh's email address

MAINTAINERS contains a lower-case and upper-case variant of
Woojung Huh' s email address.

Only keep the lower-case variant in MAINTAINERS.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS

@@ -10145,7 +10145,7 @@ F:	drivers/spi/spi-at91-usart.c
 F:	Documentation/devicetree/bindings/mfd/atmel-usart.txt
 
 MICROCHIP KSZ SERIES ETHERNET SWITCH DRIVER
-M:	Woojung Huh <Woojung.Huh@microchip.com>
+M:	Woojung Huh <woojung.huh@microchip.com>
 M:	Microchip Linux Driver Support <UNGLinuxDriver@microchip.com>
 L:	netdev@vger.kernel.org
 S:	Maintained