clk: keystone: syscon-clk: Allow the clock node to not be of type syscon

There is a helper device_node_to_regmap() we can use that does not force
this clock DT node to be a "syscon" node. It should work the same in
this case but allow us to remove the unneeded "syscon" compatible.

Signed-off-by: Andrew Davis <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Stephen Boyd <[e-mail]>

drivers/clk/keystone/syscon-clk.c

···
 	if (!data)
 		return -EINVAL;
 
-	regmap = syscon_node_to_regmap(dev->of_node);
+	regmap = device_node_to_regmap(dev->of_node);
 	if (IS_ERR(regmap))
 		return dev_err_probe(dev, PTR_ERR(regmap),
-				     "failed to find parent regmap\n");
+				     "failed to get regmap\n");
 
 	num_clks = 0;
 	for (p = data; p->name; p++)