arm: dts: socfpga: remove dma-mask property

The dma-mask property has been removed from the NAND driver. Remove the
property from the DTS files.
Signed-off-by: Dinh Nguyen <dinguyen@kernel.org>

arch/arm/boot/dts/socfpga.dtsi

@@ -746,7 +746,6 @@ nand0: nand@ff900000 {
 			      <0xffb80000 0x10000>;
 			reg-names = "nand_data", "denali_reg";
 			interrupts = <0x0 0x90 0x4>;
-			dma-mask = <0xffffffff>;
 			clocks = <&nand_clk>, <&nand_x_clk>, <&nand_ecc_clk>;
 			clock-names = "nand", "nand_x", "ecc";
 			status = "disabled";

arch/arm/boot/dts/socfpga_arria10.dtsi

@@ -653,7 +653,6 @@ nand: nand@ffb90000 {
 			      <0xffb80000 0x10000>;
 			reg-names = "nand_data", "denali_reg";
 			interrupts = <0 99 4>;
-			dma-mask = <0xffffffff>;
 			clocks = <&nand_clk>, <&nand_x_clk>, <&nand_ecc_clk>;
 			clock-names = "nand", "nand_x", "ecc";
 			status = "disabled";