Add a workaround for errata on R-Car H3 ES1.0, where the PLL0, PLL2, and
PLL4 clock frequencies are off by a factor of two.

Inspired by a patch by Dien Pham in the BSP.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Dien Pham <dien.pham.ry@renesas.com>