When changing the sysfs GT min/max frequencies, the kernel won't
explicitly change the current frequency, unless it becomes out of bound
based on the new min/max values. The test happens to work on non-VLV
platforms because on those the kernel resets the current frequency
unconditionally (to adjust the RPS interrupt mask as a side-effect) and
that will lead to an RPS interrupt setting the minimum frequency.

To fix this load the GPU after decreasing the min frequency and before
checking the current frequency. This should set the current frequency to
the minimum.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Imre Deak <imre.deak@intel.com>