There are a couple of SoCs whose names end in "pro", with the currently-
upstream examples being msm8974pro and msm8996pro. Allow such suffix in
SoC-specific compatibles.

Fixes: 5aa332c5 ("dt-bindings: qcom: document preferred compatible naming")
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20230626-topic-bindingsfixups-v1-1-254ae8642e69@linaro.org
[bjorn: Changed (pro|) to (pro)?, per Rob's request]
Signed-off-by: Bjorn Andersson <andersson@kernel.org>