power: supply: cpcap-battery: Add battery type auto detection for mapphone devices

This allows cpcap-battery to detect whitch battery is inserted, HW4X or
BW8X for xt875 and EB41 for xt894 by examining the battery nvmem. If no
known battery is detected sane defaults are used.

Signed-off-by: Carl Philipp Klemm <philipp@uvos.xyz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>