power: supply: bd99954: remove unused struct 'battery_data'

'battery_data' is unused since the original
commit 0902f836 ("power: supply: Support ROHM bd99954 charger").

Remove it.

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Acked-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/20240528000634.196707-2-linux@treblig.org


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