hwmon: (lm75) add new-style driver binding

More LM75 updates:

 - Teach the LM75 driver to use new-style driver binding:

     * Create a second driver struct, using new-style driver binding
       methods cribbed from the legacy code.

     * Add a MODULE_DEVICE_TABLE (for "newER-style binding")

     * The legacy probe logic delegates its work to this new code.

     * The legacy driver now uses the name "lm75_legacy".

 - More careful initialization.  Chips are put into 9-bit mode so
   the current interconversion routines will never fail.

 - Save the original chip configuration, and restore it on exit.
   (Among other things, this normally turns off the mode where
   the chip is constantly sampling ... and thus saves power.)

So the new-style code should catch all chips that boards declare,
while the legacy code catches others.  This particular coexistence
strategy may need some work yet ... legacy modes might best be set
up explicitly by some tool not unlike "sensors-detect".  (Or else
completely eradicated...)

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>