kernel/power/powersuspend: add back userpace control w/ default kernel control

make kernel / userspace mode switchable

Signed-off-by: Paul Reioux
<reioux@gmail.com>

idea is taken here -
https://github.com/rmbq/android_kernel_htc_msm8960/commit/75c2830c6be673aad6f01296bbbb8734dab10d05