dt-bindings: arm: qcom: Add missing msm8960

The list of supported 'SoC's didn't include msm8960 even though
qcom,msm8960-cdp exists.

Signed-off-by: Rudraksha Gupta <guptarud@gmail.com>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230524230338.120619-1-guptarud@gmail.com