dt-bindings: phy: Add PHY_TYPE_XPCS definition

Add definition for Ethernet PCS phy type.

Signed-off-by: Dilip Kota <[e-mail]>
Acked-by: Rob Herring <[e-mail]>
Acked-By: Vinod Koul <[e-mail]>
Link: https://lore.kernel.org/r/609[e-mail]
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

include/dt-bindings/phy/phy.h

···
 #define PHY_TYPE_USB3		4
 #define PHY_TYPE_UFS		5
 #define PHY_TYPE_DP		6
+#define PHY_TYPE_XPCS		7
 
 #endif /* _DT_BINDINGS_PHY */