clk: at91: fix masterck name

The master clock is actually named masterck earlier in the driver. Having
"mck" in the parent list means that it can never be selected.

Fixes: 1eabdc2f9d ("clk: at91: add at91sam9x5 PMCs driver")
Fixes: a2038077de ("clk: at91: add sama5d2 PMC driver")
Fixes: 084b696bb5 ("clk: at91: add sama5d4 pmc driver")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Cc: <stable@vger.kernel.org> # v4.20+
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/at91/sama5d4.c

@@ -207,7 +207,7 @@ static void __init sama5d4_pmc_setup(struct device_node *np)
 	parent_names[1] = "mainck";
 	parent_names[2] = "plladivck";
 	parent_names[3] = "utmick";
-	parent_names[4] = "mck";
+	parent_names[4] = "masterck";
 	for (i = 0; i < 3; i++) {
 		char name[6];