arm64: dts: qcom: x1e80100-romulus: Keep L12B and L15B always on

arm64: dts: qcom: x1e80100-romulus: Keep L12B and L15B always on

These regulators power some electronic components onboard. They're
most likely kept online by other pieces of firmware, but you can never
be sure enough.

Fixes: 09d77be56093 ("arm64: dts: qcom: Add support for X1-based Surface Laptop 7 devices")
Reported-by: Johan Hovold <johan+linaro@kernel.org>
Signed-off-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20250304-topic-sl7_vregs_aon-v1-1-b2dc706e4157@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>