rcar_gen3: drivers: pfc: Introduce common register header file

Introduce header file which contains the shared registers and bits
between the different SoCs.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Change-Id: I5f41d39347b9d57e3efdea24ae61a16d5c7efb80
1 file changed