arm64: dts: renesas: r8a774e1: Add PWM device nodes

This patch adds PWM[0123456] device nodes to the RZ/G2H (a.k.a R8A774E1)
device tree.

Signed-off-by: Marian-Cristian Rotariu <marian-cristian.rotariu.rb@bp.renesas.com>
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Link: https://lore.kernel.org/r/20200825104455.18000-3-prabhakar.mahadev-lad.rj@bp.renesas.com


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