Implement Cpu Freq Section

When poll from sysfs, revents return POLLERR by default, handles
this edge case in this cl.

Bug: 68774444
Test: unit tested + on device tests
Change-Id: I23540299c026d3e7676497f56690e9f8646a47bd
diff --git a/cmds/incidentd/src/Section.h b/cmds/incidentd/src/Section.h
index 0a1e03e..64558a6 100644
--- a/cmds/incidentd/src/Section.h
+++ b/cmds/incidentd/src/Section.h
@@ -69,6 +69,7 @@
 
 private:
     const char* mFilename;
+    bool mIsSysfs; // sysfs files are pollable but return POLLERR by default, handle it separately
 };
 
 /**