arm64: dts: renesas: r8a779g3: Set VDDQ18_25_AVB voltage on Retronix R-Car V4H Sparro...

arm64: dts: renesas: r8a779g3: Set VDDQ18_25_AVB voltage on Retronix R-Car V4H Sparrow Hawk EVTB1

The Retronix R-Car V4H Sparrow Hawk EVTB1 uses 1V8 IO voltage supply
for VDDQ18_25_AVB power rail. Update the AVB0 pinmux to reflect the
change in IO voltage. Since the VDDQ18_25_AVB power rail is shared,
all four AVB0, AVB1, AVB2, TSN0 PFC/GPIO POC[7..4] registers have to
be configured the same way.

Correct the voltage for EVTA1 boards accordingly by patching the U-Boot
control DT in SPL.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>