dt-bindings: phy: lynx-10g: initial document

dt-bindings: phy: lynx-10g: initial document

Add a schema for the 10G Lynx SerDes. This is very similar to the modern
form of the 28G Lynx SerDes, which is very much the intention.

There is intentionally no generic fsl,lynx-10g compatible string due to
the hardware inability to report its capabilities, despite having a
common register map.

We allow both forms of #phy-cells = <1> in the top-level provider
and #phy-cells = <0> in the per-lane provider for more flexibility to
consumers, and because the kernel code is shared with the 28G Lynx which
already has that support for compatibility reasons.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260610151952.2141019-15-vladimir.oltean@nxp.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>