package/kernel: add hwmon driver for ADT7410

Add support for the ADT7410 hwmon driver, a high precision
I2C temperature sensor.

Signed-off-by: Hartmut Knaack <knaack.h@gmx.de>
[juhosg: update subject, reformat commit message]
Signed-off-by: Gabor Juhos <juhosg@openwrt.org>

SVN-Revision: 38186