ARM: dts: imx6qdl: remove fsl,ssi-dma-events

All dtsi files where already moved to generic dma bindings. Remove the
old non-generic DMA properties.
Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

arch/arm/boot/dts/imx6qdl.dtsi

@@ -272,7 +272,6 @@ ssi1: ssi@02028000 {
 					       <&sdma 38 1 0>;
 					dma-names = "rx", "tx";
 					fsl,fifo-depth = <15>;
-					fsl,ssi-dma-events = <38 37>;
 					status = "disabled";
 				};
 
@@ -287,7 +286,6 @@ ssi2: ssi@0202c000 {
 					       <&sdma 42 1 0>;
 					dma-names = "rx", "tx";
 					fsl,fifo-depth = <15>;
-					fsl,ssi-dma-events = <42 41>;
 					status = "disabled";
 				};
 
@@ -302,7 +300,6 @@ ssi3: ssi@02030000 {
 					       <&sdma 46 1 0>;
 					dma-names = "rx", "tx";
 					fsl,fifo-depth = <15>;
-					fsl,ssi-dma-events = <46 45>;
 					status = "disabled";
 				};