cpufreq: Add SM6375 to cpufreq-dt-platdev blocklist

[ Upstream commit faf28e24 ]

The Qualcomm SM6375 platform uses the qcom-cpufreq-hw driver, so add
it to the cpufreq-dt-platdev driver's blocklist.

Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>