cpufreq: dt: always allocate zeroed cpumask

cpufreq: dt: always allocate zeroed cpumask

Commit 0499a78369ad ("ARM64: Dynamically allocate cpumasks and increase
supported CPUs to 512") changed the handling of cpumasks on ARM 64bit,
what resulted in the strange issues and warnings during cpufreq-dt
initialization on some big.LITTLE platforms.

This was caused by mixing OPPs between big and LITTLE cores, because
OPP-sharing information between big and LITTLE cores is computed on
cpumask, which in turn was not zeroed on allocation. Fix this by
switching to zalloc_cpumask_var() call.

Fixes: dc279ac6e5b4 ("cpufreq: dt: Refactor initialization to handle probe deferral properly")
CC: stable@vger.kernel.org # v5.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Christoph Lameter (Ampere) <cl@linux.com>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>