PM: devfreq: Fix the fast ramp case in the adreno governor

Expected behavior of GPU DCVS is to immediately bump the frequency
to turbo upon encountering a long block of busy processing.  The
current code just raises the frequency by one level.

Change-Id: Ida953bb7be8a976da5400328a1c91083499e0fa0
Signed-off-by: Lucille Sylvester <lsylvest@codeaurora.org>