macintosh: therm_pm72: delete deprecated driver

The new driver is around for more than 2 years now, so the old one can
go. Getting rid of it helps the removal of the legacy .attach_adapter
callback of the I2C subsystem.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>