MAINTAINERS: power: supply: use Krzysztof Kozlowski's Canonical address

Switch to Canonical address in S3C power supply driver, just like in
other entries.

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