Revert "Add OC to Defconfig"

This reverts commit 9f5e57c38b5b637da3cd5427511e13d6a6c22544.
Revert "acpuclock: refactor OC clock speeds a bit for consistency"

This reverts commit 5d5e61ec69d94e8a774637d478983195c0230f99.
Revert "acpuclock: initial overclock implementation"

This reverts commit 0ff98434bd21c349a64f0f48c256f932093d70d8.