power: fix sysfs_read/sysfs_write usage

* The incoming path to sysfs_read/sysfs_write should be const, as in
  open(2) call.
* Redefine scaling_gov_path as const pointer array.
* Since sysfs_read works on a simple absolute path anyway, make sure
  the scaling_gov_path paths *are* absolute.  Otherwise the code only
  works if Power HAL has / as CWD, which is a bit fragile.

Change-Id: I70c08f8137842569514bcb3f6e0617d46044e6ab
Signed-off-by: Corinna Vinschen <xda@vinschen.de>
2 files changed