phy: Add MIPI D-PHY configuration options

Now that we have some infrastructure for it, allow the MIPI D-PHY phy's to
be configured through the generic functions through a custom structure
added to the generic union.

The parameters added here are the ones defined in the MIPI D-PHY spec, plus
the number of lanes in use. The current set of parameters should cover all
the potential users.

Signed-off-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>