video/drm: display-serdes: improve detection function for split modeSigned-off-by: Luo Wei <lw@rock-chips.com>Change-Id: I8cac840bb7c7bad4c2831470b7c3bfcddb450241
video/drm: display-serdes: add split function support for maxim chipsSigned-off-by: Luo Wei <lw@rock-chips.com>Change-Id: Ia81a68020254075991932645e1587db1da90c474