adreno_tz: Remove partner devfreq management

Remove partner (bus) devfreq management from the adreno governor.
Partner devfreq can be managed directly from the device driver.

Change-Id: I745361c2b585e0dd91f208e09ec3001d7ecba717
Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>