s4-common: Use hw_get_module_by_class for camera wrapper

Change-Id: I20c123333f70ade2606a80a8f6d7145e3406e6d7
perf.profiles: cores online when setting

If cores are not online when setting freqs or governors, the
settings will not work because the files in /sys/... do not
exit when offline.

Change-Id: I6273bcc8f648d7694de86a4c1857d0b6715eb668
s4-common: Restrict square preview resolutions from VGA front camera

* The VGA front camera found in fireball and ville appears to be
  incapable of actually using a square preview resolution. Restrict it.
* Addresses failures in certain apps such as Snapchat.
* Resolves INSTALLER-89

Change-Id: I5f65942cdbebc66c3f0d43095e10f3b451bae9b3