drm/i915: Move dev_priv->pm_i{m, e}r into intel_gt

drm/i915: Move dev_priv->pm_i{m, e}r into intel_gt

PM interrupts belong to the GT so move the variables to be inside
struct intel_gt.

Signed-off-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Co-developed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Acked-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20190704121756.27824-3-tvrtko.ursulin@linux.intel.com