clk: renesas: Renesas R9A06G032 clock driver

This provides a clock driver for the Renesas R09A06G032.
This uses a structure derived from both the R-Car Gen2 driver as well as
the renesas-cpg-mssr driver.

Signed-off-by: Michel Pollet <michel.pollet@bp.renesas.com>
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>