power: supply: pm2301: drop duplicated i2c_device_id

The driver defines two of 'struct i2c_device_id' but uses only one:

  drivers/power/supply/pm2301_charger.c:107:35: warning:
    'pm2xxx_ident' defined but not used [-Wunused-const-variable=]

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>