ARM: shmobile: r8a7778: implement SoC and board CCF support

Disables the legacy clock framework and passes the mode bits to the CPG
driver if CCF is enabled.

Signed-off-by: Ulrich Hecht <ulrich.hecht+renesas@gmail.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>