ARM: dts: stm32: Use new media bus type macros

Now that a header exists with macros for the media interface bus-type
values, replace hardcoding numerical constants with the corresponding
macros in the DT sources.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>