Enable Reading for debugfs file for non-root

The file cnss_runtime_pm is created in debugfs with read
permissions limited to root user (400).
For services in the framework to be able to read the file,
we need to change that to be readable by others

Bug: 62714309
Test: Manual test

Change-Id: I92f63e11ae63e4551c48d421d3805adc6e388341
Signed-off-by: Ahmed ElArabawy <arabawy@google.com>