phy: qcom: qmp-usb-legacy: drop single-lane support

All PHYs supported by usb-legacy have two lanes. Drop support for
single-lane configuration.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Konrad DYbcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20240126-phy-qmp-merge-common-v2-1-a463d0b57836@linaro.org


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