MAINTAINERS: Remove Olof from SoC maintainers

I haven't been an active participant for a couple of years now, and
after discussions at Linux Plumbers in 2024, Arnd is getting fresh help
from a few more participants.

It's time to remove myself, and spare myself from patches and pull
requests in my inbox.

Signed-off-by: Olof Johansson <olof@lixom.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Author: olofj

MAINTAINERS

@@ -1797,7 +1797,6 @@ F:	include/uapi/linux/if_arcnet.h
 
 ARM AND ARM64 SoC SUB-ARCHITECTURES (COMMON PARTS)
 M:	Arnd Bergmann <arnd@arndb.de>
-M:	Olof Johansson <olof@lixom.net>
 L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
 L:	soc@lists.linux.dev
 S:	Maintained