battery: support additional properties

Support additional properties from the linux `battery.yaml`.

The `ocv-capacity-table-0` definition differs from the Linux version as
we do not have a good way to generate variable length arrays in our
config structs, or a good way to separate out the percentage vs voltage
in the mapping.

We reduce the flexibility by enforcing a step size of 10%, which removes
the need for the percentage to be in the array and solves the variable
length problem.

To simplify the effort of defining these voltage curves, default curves
for a variety of chemistries have been added, extracted from datasheet
graphs of discharge curves from reputable manufacturers.

Signed-off-by: Jordan Yates <jordan@embeint.com>