pinctrl: sh-pfc: r8a7795: Correct header from R-Car Gen3 to R8A7795

This source file handles r8a7795 only, which is not the sole member of
the R-Car Gen3 family.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/sh-pfc/pfc-r8a7795.c

 /*
- * R-Car Gen3 processor support - PFC hardware block.
+ * R8A7795 processor support - PFC hardware block.
  *
  * Copyright (C) 2015  Renesas Electronics Corporation
  *