dt-bindings: phy: drop obsolete qcom,usb-8x16-phy bindings

Remove the bindings for the Qualcomm 8x16 PHY driver that was dropped
in commit 4756f35 ("usb: phy: remove phy-qcom-8x16-usb.c") in 2017.

Signed-off-by: Rayyan Ansari <rayyan.ansari@linaro.org>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://lore.kernel.org/r/20240711122016.41806-1-rayyan.ansari@linaro.org
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: RayyanAnsari