synaptics_dsx_i2c: Handle prevent_sleep when we need to
input: sweep2wake: Update various driver bits
 - Allow debug/pwrkey_dur tuneables to be altered via sysfs
 - Clean logtags up for end-users/future bringup
 - Remove single_touch instance, it was just a hardcoded anyway
 - Only debug when sweep2wake is usable (screen on + s2s/screen off + s2w)
 - Remove s2w_version_show() - We can just use 'NULL' if we don't want to write