power: supply: axp20x_usb_power: use correct register for input current limit

power: supply: axp20x_usb_power: use correct register for input current limit

On the axp803 and axp813 chips register 0x30 bits 0-1 is the default
current limit that gets applied after the pmic detects a CDP or DCP
port. The correct field to set is 0x35 bits 4-7.

This field only has nine values (out of the 16 possible if it used all
the bits), so introduce a field size variable to take that into account.

Signed-off-by: Aren Moynihan <aren@peacevolution.org>
Link: https://lore.kernel.org/r/20240130203714.3020464-3-aren@peacevolution.org
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>