drm/bridge: fsl-ldb: Allow the termination resistor to be enabled

drm/bridge: fsl-ldb: Allow the termination resistor to be enabled

The LVDS Control Register (LVDS_CTRL) register has an HS_EN bit that allows
the 100 Ohm termination resistor in the chip to be enabled.

Add support to setting the HS_EN bit when the optional property
"nxp,enable-termination-resistor" is present.

The motivation for introducing this property was a custom i.MX8MP board
that was showing visual artifacts. After enabling the 100 Ohm termination
resistor the LVDS signal quality improved causing the artifacts to
disappear.

Signed-off-by: Fabio Estevam <festevam@nabladev.com>
Reviewed-by: Liu Ying <victor.liu@nxp.com>
Signed-off-by: Liu Ying <victor.liu@nxp.com>
Link: https://lore.kernel.org/r/20260120231930.2782444-2-festevam@gmail.com