ARM: dts: socfpga: add pl330 clock

The pl330 dmac won't be added to the list of amba devices, as it doesn't have
a clock entry.
Add the clock.

Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Dinh Nguyen <dinguyen@altera.com>
diff --git a/arch/arm/boot/dts/socfpga.dtsi b/arch/arm/boot/dts/socfpga.dtsi
index efcc38a..537f1a5 100644
--- a/arch/arm/boot/dts/socfpga.dtsi
+++ b/arch/arm/boot/dts/socfpga.dtsi
@@ -79,6 +79,8 @@
 				#dma-cells = <1>;
 				#dma-channels = <8>;
 				#dma-requests = <32>;
+				clocks = <&l4_main_clk>;
+				clock-names = "apb_pclk";
 			};
 		};