phy: Add MIPI D-PHY mode

MIPI D-PHY is a MIPI standard meant mostly for display and cameras in
embedded systems. Add a mode for it.

Reviewed-by: Laurent Pinchart <[e-mail]>
Reviewed-by: Sakari Ailus <[e-mail]>
Signed-off-by: Maxime Ripard <[e-mail]>
Signed-off-by: Kishon Vijay Abraham I <[e-mail]>

include/linux/phy/phy.h

···
 	PHY_MODE_UFS_HS_B,
 	PHY_MODE_PCIE,
 	PHY_MODE_ETHERNET,
+	PHY_MODE_MIPI_DPHY,
 };
 
 /**