dt-bindings: phy: qcom,pcie2-phy: convert to YAML format

Convert the bindings for the Qualcomm PCIe2 PHY into the YAML format
from the text description.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20221229115932.3312318-2-dmitry.baryshkov@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>