clk: renesas: r8a779a0: Add CSI4[0-3] clocks

Add definitions of the CSI-2 receiver clocks for R-Car V3U.

Signed-off-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Link: https://lore.kernel.org/r/20201016111158.17521-2-jacopo+renesas@jmondi.org


Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>