clk: renesas: Split RCar Gen3 driver

Split the massive driver into smaller per-SoC drivers and pull the
common code into a separate file. This would allow configuring out
unnecessary clock drivers once the Kconfig changes are in and also
allow adding more clock tables easily.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
7 files changed