arm64: dts: renesas: r8a774b1: Add I2C and IIC-DVFS support

Add the I2C[0-6] and IIC Bus Interface for DVFS (IIC for DVFS)
devices nodes to the r8a774b1 device tree.

Signed-off-by: Biju Das <biju.das@bp.renesas.com>
Link: https://lore.kernel.org/r/1569313375-53428-3-git-send-email-biju.das@bp.renesas.com


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