defconfigs: Enable conservative governor

also fix default cpu clock min speed
Squashed update of kernel from 3.4.70 to 3.4.71
Squashed update of kernel from 3.4.71 to 3.4.72
Squashed update of kernel from 3.4.72 to 3.4.73
Squashed update of kernel from 3.4.73 to 3.4.74
Revert zRAM updates from kernel 3.12

zRAM crashes all the time, let's use the 3.4 default