Enable/Disable MGBE loopback mode by set/clear loopback mode (MGBE_MAC_RMCR_LM) in MAC receive configuration. Bug 200565892 Change-Id: Ibd23b264623d9a8b80b7fbe743167df94cd93baf Signed-off-by: Bhadram Varka <vbhadram@nvidia.com> Reviewed-on: https://git-master.nvidia.com/r/c/kernel/nvethernetrm/+/2252672