MAINTAINERS: friendly takeover of i2c-gpio driver

I haven't heard from Haavard in years despite putting him to the CC list for
i2c-gpio related mails. Since I was doing the work on this driver for a while
now, let me take official maintainership, so it will be more clear to users.

Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: Haavard Skinnemoen <hskinnemoen@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>

MAINTAINERS

@@ -6461,7 +6461,7 @@ S:	Maintained
 F:	drivers/media/radio/radio-gemtek*
 
 GENERIC GPIO I2C DRIVER
-M:	Haavard Skinnemoen <hskinnemoen@gmail.com>
+M:	Wolfram Sang <wsa+renesas@sang-engineering.com>
 S:	Supported
 F:	drivers/i2c/busses/i2c-gpio.c
 F:	include/linux/platform_data/i2c-gpio.h