Align file permissions for cpufreq scaling_max_freq node

The ueventd.rc sets permissions to 0664 but init.rc sets cpu0 to
0660. Since lots of processes already had read access for cpufreq nodes
(refer to system/sepolicy/public/domain.te), align all cpus to 0644
permissions.

Bug: 230291215
Test: Build
Change-Id: I3c72d69590998f8da894fb02097212f834edd48c