NetworkPkg: remove unnecessary timeout event when setting IPv6 address.

NetworkPkg: remove unnecessary timeout event when setting IPv6 address.

Use Ip6Cfg->SetData() to set IP6 manual address is asynchronous process and the
registered data notify event will be singled when process is done. So it's not
necessary to create another timeout event for the address setting.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Ye Ting <ting.ye@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18610 6f19259b-4bc3-4df7-8a09-765794883524