dt-bindings: remoteproc: qcom: Fixup regulator dependencies

Fixup regulator supply dependencies for Q6V5 MSS on MSM996 SoCs.

Fixes: 9f058fa2 ("remoteproc: qcom: Add support for mss remoteproc on msm8996")
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sibi Sankar <sibis@codeaurora.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>