power: supply: cpcap-battery: Read and save integrator register CCI

We can simplify code in the later patches by reading and saving the
integrator register CCI. Let's also fix a comment typo for register range
naming while at it.

Cc: Merlijn Wajer <merlijn@wizzup.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>