lm85: fix the version check that broke adt7468 probing

The verstep check in the lm85 driver fails because the upper nibble of
the version register is 0x7, not 0x6, on the adt7468 chip.  Probing of
all adt7468s was broken by 69fc1feb
("hwmon: (lm85) Rework the device detection"), and this patch fixes
that.  Also add in a missing i2c_device_id that accidentally got dropped
from the original patch.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Cc: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>