regulator: cpcap: Fix standby mode

The original patch from Tony uses standby mode bit inverted, which is
not correct. This fixes all instances in the driver code for get & set
mode. This did not yet make problems, since mode has not been changed
by any mainline driver so far.

Fixes: 0ad4c07e ("regulator: cpcap: Add basic regulator support")
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org