dt-bindings: cpufreq: cpufreq-qcom-hw: Add missing constraint for interrupt-names

When narrowing properties per variant, the 'interrupt-names' should have
the same constraints as 'interrupts'.  Add missing upper bound on the
property.

Fixes: e6900320 ("dt-bindings: cpufreq: cpufreq-qcom-hw: Add QCM2290")
Fixes: 7ae24e05 ("dt-bindings: cpufreq: cpufreq-qcom-hw: Sanitize data per compatible")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>