dt-bindings: phy: Add PHY_TYPE_QSGMII definition

Add definition for QSGMII phy type.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1600327846-9733-5-git-send-email-sjakhade@cadence.com


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