dt-bindings: soc: qcom: smd-rpm: re-add missing qcom,rpm-msm8994

Re-add the qcom,rpm-msm8994 compatible, dropped during conversion from
TXT to DT schema:

  apq8094-sony-xperia-kitakami-karin_windy.dtb: smd: rpm:rpm-requests:compatible:0: 'qcom,rpm-msm8994' is not one of ['qcom,rpm-apq8084' ...]

Fixes: f935a752 ("dt-bindings: soc: qcom: smd-rpm: Convert binding to YAML schema")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Petr Vorel <petr.vorel@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230305122428.167580-1-krzysztof.kozlowski@linaro.org