regulator: twl: Fix a typo in twl4030_send_pb_msg

Commit <2330b05c> ("regulator: twl: Make
sure we have access to powerbus before trying to write to it")
has implemented the needed logic to correctly access powerbus through i2c,
however it brought a typo when powerbus configuration is restored, which
results in writing to a wrong register. Fix that by providing the correct
register value.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>