drm/i915: Fix debugfs PDP register dump

Iterate over all the PDP registers instead of just printing PDP0 four
times in gen8 PPGTT debugfs info.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -1830,8 +1830,7 @@ static void gen8_ppgtt_info(struct seq_file *m, struct drm_device *dev)
 			u64 pdp = I915_READ(ring->mmio_base + offset + 4);
 			pdp <<= 32;
 			pdp |= I915_READ(ring->mmio_base + offset);
-			for (i = 0; i < 4; i++)
-				seq_printf(m, "\tPDP%d 0x%016llx\n", i, pdp);
+			seq_printf(m, "\tPDP%d 0x%016llx\n", i, pdp);
 		}
 	}
 }