dt-bindings: phy: qcom,qmp-pcie: Add X1P42100 PCIe Gen4x4 PHY

X1P42100 has two Gen4x4 PHYs instead of one Gen4x4 and one Gen4x8.

They are mostly identical to X1E80100's Gen4x4 PHY, but there are some
minor details in the programming sequences.

Introduce a new compatible for this flavor of the PHY.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250203-topic-x1p4_dts-v2-1-72cd4cdc767b@oss.qualcomm.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>