power: batterydata-lib: Add IOCTLs to read battery-profile

Add IOCTLs to access battery profile data from userspace.
This avoids duplicating the battery-profile data in the
userspace.

To support this add a character device and expose an API
to set the battery profile.

Change-Id: I2ecc75e3c33f9a814f02426ba8d9a22cdc661c2b
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>