DeviceInfo: Add chipset to supplement cpu display in device info

Use ro.device.chipset to display chipset name along with cpu info
in device info settings.

For example:
ro.device.chipset=Qualcomm Snapdragon S4 Pro APQ8064
ro.device.cpu=1.5GHz quad-core Krait

With the Krait, a15, a9, plus dual-cores/quad-cores AND
the various names Exynos, OMAP, Snapdragom msmXXXX, etc
its all fun info, but its a bit much for one line.

Separate them out so we can display it all but not
exceed twitter's 140 character limit.

Change-Id: I5c2c58d16d0e7fa1344d6290a67e1281c710c3fb