mfd: sec-core: Add support for S2MPU02 device

Add support for Samsung S2MPU02 PMIC device to the MFD sec-core driver.
The S2MPU02 device includes PMIC/RTC/Clock devices.

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>