[ARM] pxa/cm-x300: add da9030 support

Register DA9030 PMIC. Use only backlight sub-device for now.

Signed-off-by: Igor Grinberg <grinberg@compulab.co.il>
Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: Eric Miao <eric.y.miao@gmail.com>