dt-bindings: clock: renesas: rcar-usb2-clock-sel: Fix typo in example

The documented compatible value for R-Car H3 is
"renesas,r8a7795-rcar-usb2-clock-sel", not
"renesas,r8a77950-rcar-usb2-clock-sel".

Fixes: 311accb6 ("clk: renesas: rcar-usb2-clock-sel: Add R-Car USB 2.0 clock selector PHY")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20191016145650.30003-1-geert+renesas@glider.be