drm/i915: Do RPM Wake during GuC/HuC status read

HUC_STATUS, GUC_STATUS, SOFT_SCRATCH registers are read in debugfs
and getparam ioctl. This patch covers those accesses by RPM get/put.

v2: Covering access in i915_getparam(I915_PARAM_HUC_STATUS) (ChrisW)

Cc: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Cc: Anusha Srivatsa <anusha.srivatsa@intel.com>
Cc: Fiedorowicz, Lukasz <lukasz.fiedorowicz@intel.com>
Signed-off-by: Sagar Arun Kamble <sagar.a.kamble@intel.com>
Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1486110513-12130-1-git-send-email-sagar.a.kamble@intel.com