dt-bindings: clock: renesas: rcar-usb2-clock-sel: Fix clock[-name]s properties

Since the hardware requires to enable both USB 2.0 host and peripheral
functional clock, this patch fixes the documentation.
Fortunately, no one has this device node for now, so that we don't
need to think of backward compatibility.

Fixes: 311accb6

 ("clk: renesas: rcar-usb2-clock-sel: Add R-Car USB 2.0 clock selector PHY")
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/1583304137-28482-2-git-send-email-yoshihiro.shimoda.uh@renesas.com


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