[U-Boot] Rework needed for SMDK5250 re PMIC to POWER transition

Hello,

Commit 0d146a56 (from Rajesh, applied by Minkyu) introduced SMDK5250 support for the MAX77686 pmic chip. However, u-boot/master has reworks for PMIC that make this support break when merging u-boot-arm and u-boot.

Rajesh, can you look into it and provide a fix to Minkyu?

Minkyu, can you add this to the fix pull request already needed for universal?

Thanks in advance!

Amicalement,