Battery Friend: Fix value input.

Frequencies set by user weren't stored before
Revert "sys/kernel/power: Front Buffer Delay: Rename the kobject to 'fbu_delay' to avoid conflict with GAMMA control in Trickster Mod app - only for now until this wil be fixed in TM"

This reverts commit 5c818c811a5e8cc39b3dcb5e12ceb5fe3cf886d5.