MAINTAINERS: change my mail to the kernel.org one

As I'm doing more and more work professionally, move away from my
private mail address.
Signed-off-by: Michael Walle <michael@walle.cc>
Link: https://lore.kernel.org/r/20231219091218.2846297-1-michael@walle.ccSigned-off-by: Tudor Ambarus <tudor.ambarus@linaro.org>

MAINTAINERS

@@ -9045,7 +9045,7 @@ F:	drivers/gpio/gpio-mockup.c
 F:	tools/testing/selftests/gpio/
 
 GPIO REGMAP
-M:	Michael Walle <michael@walle.cc>
+M:	Michael Walle <mwalle@kernel.org>
 S:	Maintained
 F:	drivers/gpio/gpio-regmap.c
 F:	include/linux/gpio/regmap.h
@@ -19901,7 +19901,7 @@ W:	http://www.winischhofer.at/linuxsisusbvga.shtml
 F:	drivers/usb/misc/sisusbvga/
 
 SL28 CPLD MFD DRIVER
-M:	Michael Walle <michael@walle.cc>
+M:	Michael Walle <mwalle@kernel.org>
 S:	Maintained
 F:	Documentation/devicetree/bindings/gpio/kontron,sl28cpld-gpio.yaml
 F:	Documentation/devicetree/bindings/hwmon/kontron,sl28cpld-hwmon.yaml
@@ -19916,7 +19916,7 @@ F:	drivers/pwm/pwm-sl28cpld.c
 F:	drivers/watchdog/sl28cpld_wdt.c
 
 SL28 VPD NVMEM LAYOUT DRIVER
-M:	Michael Walle <michael@walle.cc>
+M:	Michael Walle <mwalle@kernel.org>
 S:	Maintained
 F:	Documentation/devicetree/bindings/nvmem/layouts/kontron,sl28-vpd.yaml
 F:	drivers/nvmem/layouts/sl28vpd.c
@@ -20426,7 +20426,7 @@ F:	drivers/pinctrl/spear/
 SPI NOR SUBSYSTEM
 M:	Tudor Ambarus <tudor.ambarus@linaro.org>
 M:	Pratyush Yadav <pratyush@kernel.org>
-M:	Michael Walle <michael@walle.cc>
+M:	Michael Walle <mwalle@kernel.org>
 L:	linux-mtd@lists.infradead.org
 S:	Maintained
 W:	http://www.linux-mtd.infradead.org/