ls1021a: QSPI: update the node for QSPI support

Add the name for register space and memory space.
<0x1550000 0x10000 > is the QSPI register space.
<0x40000000 0x4000000> is the QSPI memory space.
Signed-off-by: NYuan Yao <yao.yuan@nxp.com>
Reviewed-by: NYork Sun <york.sun@nxp.com>

arch/arm/dts/ls1021a.dtsi

@@ -176,6 +176,7 @@
 			#size-cells = <0>;
 			reg = <0x1550000 0x10000>,
 				<0x40000000 0x4000000>;
+			reg-names = "QuadSPI", "QuadSPI-memory";
 			num-cs = <2>;
 			big-endian;
 			status = "disabled";