arm64: dts: renesas: beacon: Fix audio-1.8V pin enable

arm64: dts: renesas: beacon: Fix audio-1.8V pin enable

[ Upstream commit 5a5da0b758b327b727c5392d7f11e046e113a195 ]

The fact the audio worked at all was a coincidence because the wrong
gpio enable was used.  Use the correct GPIO pin to ensure its operation.

Fixes: a1d8a344f1ca ("arm64: dts: renesas: Introduce r8a774a1-beacon-rzg2m-kit")
Signed-off-by: Adam Ford <aford173@gmail.com>
Link: https://lore.kernel.org/r/20201213183759.223246-6-aford173@gmail.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>