MAINTAINERS: Remove linuxwwan@intel.com mailing list

Messages submitted to the ML bounce (address not found error). In
fact, the ML was mistagged as person maintainer instead of mailing
list.

Remove the ML to keep Cc: lists a bit shorter and not to spam
everyone's inbox with postmaster notifications.

Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20231025130332.67995-2-bagasdotme@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>