MAINTAINERS: Remove myself as maintainer

I am leaving Axis, so this address will bounce in the not too
distant future.

Fortunately, I will still be working with the community.
Signed-off-by: Niklas Cassel <niklas.cassel@axis.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

MAINTAINERS

@@ -1208,7 +1208,6 @@ F:	drivers/*/*alpine*
 ARM/ARTPEC MACHINE SUPPORT
 M:	Jesper Nilsson <jesper.nilsson@axis.com>
 M:	Lars Persson <lars.persson@axis.com>
-M:	Niklas Cassel <niklas.cassel@axis.com>
 S:	Maintained
 L:	linux-arm-kernel@axis.com
 F:	arch/arm/mach-artpec
@@ -10909,7 +10908,6 @@ F:	drivers/pci/host/
 F:	drivers/pci/dwc/
 
 PCIE DRIVER FOR AXIS ARTPEC
-M:	Niklas Cassel <niklas.cassel@axis.com>
 M:	Jesper Nilsson <jesper.nilsson@axis.com>
 L:	linux-arm-kernel@axis.com
 L:	linux-pci@vger.kernel.org