arm64: defconfig: Enable DA9211 regulator

arm64: defconfig: Enable DA9211 regulator

Mediatek mt8173 board fails to boot with DA9211 regulator disabled.
Enabling CONFIG_REGULATOR_DA9211=y in drm-ci fixes the issue.

So enable it in the defconfig since kernel-ci also requires it.

Suggested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Vignesh Raman <vignesh.raman@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20230911104139.617448-1-vignesh.raman@collabora.com
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>