am335x-nmhw21 systemd.conf: Remove machine specific config file

Use default machine independent configuration file.
Reverts also DefaultTimeoutStopSec=10s since this killed
GNSS save on shutdown service.

BugzID: 63924

Signed-off-by: Ramon Moesching <ramon.moesching@netmodule.com>

recipes-core/systemd/systemd-conf/am335x-nmhw21/system.conf

@@ -1,57 +0,0 @@
-#  This file is part of systemd.
-#
-#  systemd is free software; you can redistribute it and/or modify it
-#  under the terms of the GNU Lesser General Public License as published by
-#  the Free Software Foundation; either version 2.1 of the License, or
-#  (at your option) any later version.
-#
-# Entries in this file show the compile time defaults.
-# You can change settings by editing this file.
-# Defaults can be restored by simply deleting this file.
-#
-# See systemd-system.conf(5) for details.
-
-[Manager]
-#LogLevel=info
-#LogTarget=journal-or-kmsg
-#LogColor=yes
-#LogLocation=no
-#DumpCore=yes
-#CrashShell=no
-#ShowStatus=yes
-#CrashChVT=1
-#CPUAffinity=1 2
-#JoinControllers=cpu,cpuacct net_cls,net_prio
-#RuntimeWatchdogSec=20s
-#ShutdownWatchdogSec=10min
-#CapabilityBoundingSet=
-#SystemCallArchitectures=
-#TimerSlackNSec=
-#DefaultTimerAccuracySec=1min
-#DefaultStandardOutput=journal
-#DefaultStandardError=inherit
-#DefaultTimeoutStartSec=90s
-DefaultTimeoutStopSec=10s
-#DefaultRestartSec=100ms
-#DefaultStartLimitInterval=10s
-#DefaultStartLimitBurst=5
-#DefaultEnvironment=
-#DefaultCPUAccounting=no
-#DefaultBlockIOAccounting=no
-#DefaultMemoryAccounting=no
-#DefaultLimitCPU=
-#DefaultLimitFSIZE=
-#DefaultLimitDATA=
-#DefaultLimitSTACK=
-#DefaultLimitCORE=
-#DefaultLimitRSS=
-#DefaultLimitNOFILE=
-#DefaultLimitAS=
-#DefaultLimitNPROC=
-#DefaultLimitMEMLOCK=
-#DefaultLimitLOCKS=
-#DefaultLimitSIGPENDING=
-#DefaultLimitMSGQUEUE=
-#DefaultLimitNICE=
-#DefaultLimitRTPRIO=
-#DefaultLimitRTTIME=