dt-bindings: phy: Add support for QMP phy

Qualcomm chipsets have QMP phy controller that provides
support to a number of controller, viz. PCIe, UFS, and USB.
Adding dt binding information for the same.

Signed-off-by: Vivek Gautam <vivek.gautam@codeaurora.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>