PM / devfreq: exynos-ppmu: Show the registred device for ppmu device

This patch just adds the simple log to show the PPMU device's registration
during the kernel booting.

Cc: Kukjin Kim <[e-mail]>
Cc: Krzysztof Kozlowski <[e-mail]>
Cc: Javier Martinez Canillas <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Signed-off-by: Chanwoo Choi <[e-mail]>
Signed-off-by: MyungJoo Ham <[e-mail]>

drivers/devfreq/event/exynos-ppmu.c

···
 				"failed to add devfreq-event device\n");
 			return PTR_ERR(edev[i]);
 		}
+
+		pr_info("exynos-ppmu: new PPMU device registered %s (%s)\n",
+			dev_name(&pdev->dev), desc[i].name);
 	}
 
 	clk_prepare_enable(info->ppmu.clk);