Intel MID platform battery driver

The PMIC Battery driver provides battery charging and battery gauge
functionality on Intel MID platforms. This provides the basic functions.
There are some USB drivers to merge before the selection of charging
between the different USB power levels can be enabled.

Moved to a platform device by Alek Du.

Signed-off-by: Nithish Mahalingam <nithish.mahalingam@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>