[CPUFREQ] fix (utter) cpufreq_add_dev mess

[CPUFREQ] fix (utter) cpufreq_add_dev mess

OK, I've tried to clean it up the best I could, but please test this with
concurrent cpu hotplug and cpufreq add/remove in loops. I'm sure we will make
other interesting findings.

This is step one of fixing the overall locking dependency mess in cpufreq.

Signed-off-by: Mathieu Desnoyers <[email protected]>
CC: Venkatesh Pallipadi <[email protected]>
CC: [email protected]
CC: [email protected]
CC: Shaohua Li <[email protected]>
CC: Pekka Enberg <[email protected]>
CC: Dave Young <[email protected]>
CC: "Rafael J. Wysocki" <[email protected]>
CC: Rusty Russell <[email protected]>
CC: [email protected]
CC: [email protected]
CC: Thomas Renninger <[email protected]>
Signed-off-by: Dave Jones <[email protected]>