[CELL] cbe_cpufreq: fix initialization

This patch fixes the initialization of the cbe_cpufreq driver.
The code that initializes the PMI related functions was called per cpu:
* registering cpufreq notifier block
* registering a pmi handler

This ends in a bug that the notifier block gets called in an endless loop.
The initialization code is being put to the
module init code path by this patch. This way it only gets called once.

Signed-off-by: Christian Krafft <krafft@de.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>