intelli_plug: Replace __cpuinit with __ref

This is a partial revert of 8c93137 (intelli_plug: get rid of __cpuinit), and
replaces __cpuinit with __ref.

Adapted from AOSP upstream commit Ifa413f6708935b1dcae9438bf39a194372eb0c61

__cpuinit is causing issues on non smp targets and it also leads to
compilation issues if __cpuinit is completely removed on smp targets
as modpost will complain for calling removable sections from non
removable sections. Replace __cpuinit data with __ref which will
silence the modpost and works fine for non smp targets as well.

Change-Id: I333773012ab556c1e2da3f3029c29f056d5dae14
Signed-off-by: Rob Beane <robbeane@gmail.com>