serrano: Remove useless lpm.rc file

Change-Id: Ia6bd0096f103fa18a373f5d89318e61c3dec0a5d
serrano-common: Set SSR level

Control SSR level from sysfs and set to independent reset to allow a
crashed component, ie modem, to reset itself without taking the system
down.

Requires http://review.cyanogenmod.org/#/c/66317/

Change-Id: Ide411656d71b5bae35e3cb86cc72371fb301e1a2