power: supply: max77693_charger: fix unintentional fall-through

It seems that a *break* is missing in order to avoid a fall-through.
Otherwise, the calculation of *data* makes no sense.

Addresses-Coverity-ID: 1271172 ("Missing break in switch")
Fixes: 87c2d906 ("power: max77693: Add charger driver for Maxim 77693")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>