drm/i915: Add more keywords to firmware loading message

To find out what firmware we actually loaded (from dmesg) the explicit
'dmc' and 'firmware' are missing from the info printout. Add them.

Cc: Imre Deak <imre.deak@intel.com>
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NMika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1479288806-17355-1-git-send-email-mika.kuoppala@intel.com

drivers/gpu/drm/i915/intel_csr.c

@@ -405,7 +405,7 @@ static void csr_load_work_fn(struct work_struct *work)
 
 		intel_display_power_put(dev_priv, POWER_DOMAIN_INIT);
 
-		DRM_INFO("Finished loading %s (v%u.%u)\n",
+		DRM_INFO("Finished loading DMC firmware %s (v%u.%u)\n",
 			 dev_priv->csr.fw_path,
 			 CSR_VERSION_MAJOR(csr->version),
 			 CSR_VERSION_MINOR(csr->version));