tests/i915_pm_freq_api: Set min/max to expected values

A prior(rps) test leaves the system in a bad state causing failures
in the basic test. Set min/max to expected values before running it.
Test will restore values at the end.

Link: https://gitlab.freedesktop.org/drm/intel/-/issues/8670



Signed-off-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Reviewed-by: Riana Tauro <riana.tauro@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>