arm: dts: ls1028a: move the PCI I/O window to match
To make the synchronization of the u-boot device tree with the one from
linux easier, move the I/O window to the one which is specified in the
linux device tree. The actual value shouldn't matter as long as it
mapped to the corresponding memory window of the PCIe controller which
is a 32GiB window at 80_0000_0000h (first controller) or 88_0000_0000h
(second controller).