[ARM] Orion: activate lm75 driver on DNS-323

The lm75 driver was recently converted to the new-style binding,
so now it can be loaded from the DNS-323 support code.

Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Tested-by: Tobias Poschwatta <tp@fonz.de>
Acked-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>