clk: at91: Align clk-master compatibles with kernel

Add the compatible "atmel,at91rm9200-clk-master" to align with
the kernel.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/clk/at91/clk-master.c

@@ -21,6 +21,7 @@ static struct clk_ops at91_master_clk_ops = {
 };
 
 static const struct udevice_id at91_master_clk_match[] = {
+	{ .compatible = "atmel,at91rm9200-clk-master" },
 	{ .compatible = "atmel,at91sam9x5-clk-master" },
 	{}
 };