power: supply: core: constify power_supply_battery_info::ocv_table

The power supply core never modifies the ocv table.
Reflect this in the API, so drivers can mark their static tables as
const.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20241005-power-supply-battery-const-v1-5-c1f721927048@weissschuh.net


Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>