Revert "PM / devfreq: Modify the device name as devfreq(X) for sysfs"

This reverts commit 4585fbcb. The change
to be reverted would add probe order-dependent numbers to the end of each
devfreq device, making our post boot script (among others) incredibly
brittle.

Change-Id: I8fdb679ae651d9f425ffd60e2141613ae20bb029
Signed-off-by: Jonathan Avila <avilaj@codeaurora.org>
Signed-off-by: Rama Aparna Mallavarapu <aparnam@codeaurora.org>