enable sysfs epoll interface for 'proximity_enables' driver attribute

absolute ANGLE range is -90 to 90, not 0 to 90.

Change-Id: I8afcd4e1a13cfc9b4dcabcada77b2bfa6b93f007
change flip masks and bits for smartcover

*) use SW_LID instead of SW_FLIP
*) invert state of the flipcover

Change-Id: I620b198adbd696d0b69ae7df3b4c6fcb0c7b1b64