drm/i915: use id from intel_shared_dpll.info

Replace all users of pll->id to use pll->info->id. In functions using
this more than once it was preferred to add an id variable to make the
code easier to read.

Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180320220637.21480-6-lucas.demarchi@intel.com

drivers/gpu/drm/i915/i915_debugfs.c

@@ -3286,7 +3286,7 @@ static int i915_shared_dplls_info(struct seq_file *m, void *unused)
 		struct intel_shared_dpll *pll = &dev_priv->shared_dplls[i];
 
 		seq_printf(m, "DPLL%i: %s, id: %i\n", i, pll->info->name,
-			   pll->id);
+			   pll->info->id);
 		seq_printf(m, " crtc_mask: 0x%08x, active: 0x%x, on: %s\n",
 			   pll->state.crtc_mask, pll->active_mask, yesno(pll->on));
 		seq_printf(m, " tracked hardware state:\n");