spi: mpc512x: adjust to OF based clock lookup

after device tree based clock lookup became available, the peripheral
driver need no longer construct clock names which include the PSC index,
remove the "psc%d_mclk" template and unconditionally use 'mclk'

acquire and release the 'ipg' clock item for register access as well

Cc: Mark Brown <[e-mail]>
Cc: [e-mail]
Signed-off-by: Gerhard Sittig <[e-mail]>
Acked-by: Mark Brown <[e-mail]>
Signed-off-by: Anatolij Gustschin <[e-mail]>

drivers/spi/spi-mpc512x-psc.c

···
 	unsigned int irq;
 	u8 bits_per_word;
 	struct clk *clk_mclk;
+	struct clk *clk_ipg;
 	u32 mclk_rate;
 
 	struct completion txisrdone;
···
 	struct spi_master *master;
 	int ret;
 	void *tempp;
-	int psc_num;
-	char clk_name[16];
 	struct clk *clk;
 
 	master = spi_alloc_master(dev, sizeof *mps);
···
 		goto free_master;
 	init_completion(&mps->txisrdone);
 
-	psc_num = master->bus_num;
-	snprintf(clk_name, sizeof(clk_name), "psc%d_mclk", psc_num);
-	clk = devm_clk_get(dev, clk_name);
+	clk = devm_clk_get(dev, "mclk");
 	if (IS_ERR(clk)) {
 		ret = PTR_ERR(clk);
 		goto free_irq;
···
 	mps->clk_mclk = clk;
 	mps->mclk_rate = clk_get_rate(clk);
 
+	clk = devm_clk_get(dev, "ipg");
+	if (IS_ERR(clk)) {
+		ret = PTR_ERR(clk);
+		goto free_mclk_clock;
+	}
+	ret = clk_prepare_enable(clk);
+	if (ret)
+		goto free_mclk_clock;
+	mps->clk_ipg = clk;
+
 	ret = mpc512x_psc_spi_port_config(master, mps);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	ret = devm_spi_register_master(dev, master);
 	if (ret < 0)
-		goto free_clock;
+		goto free_ipg_clock;
 
 	return ret;
 
-free_clock:
+free_ipg_clock:
+	clk_disable_unprepare(mps->clk_ipg);
+free_mclk_clock:
 	clk_disable_unprepare(mps->clk_mclk);
 free_irq:
 	free_irq(mps->irq, mps);
···
 	struct mpc512x_psc_spi *mps = spi_master_get_devdata(master);
 
 	clk_disable_unprepare(mps->clk_mclk);
+	clk_disable_unprepare(mps->clk_ipg);
 	free_irq(mps->irq, mps);
 	if (mps->psc)
 		iounmap(mps->psc);