Bluetooth: controller: Fixed conn_meta bitflag misalignment

Fixed misalignment of bitflag in ll_conn type causing unintentional
overwrite between unions. Common flag must be present in master/slave
uinons as well. Problem is only present when enabling feature
CONFIG_BT_CTLR_CONN_META, which is default disabled.

Signed-off-by: Morten Priess <mtpr@oticon.com>