pinctrl: renesas: r8a77980: Add support for AVB/GE power-sources

Add support for configuring the I/O voltage levels of the Ethernet AVB
and Gigabit Ethernet pins on the R-Car V3H SoC.  "PIN_VDDQ_AVB" and
"PIN_VDDQ_GE" can be configured for 2.5V or 3.3V operation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/3c26c4f3735a6d071685c507c065172e63af5d70.1678271030.git.geert+renesas@glider.be