arm64: dts: ls1028a: fix the offset of the reset register

The offset of the reset request register is 0, the absolute address is
0x1e60000. Boards without PSCI support will fail to perform a reset:

[   26.734700] reboot: Restarting system
[   27.743259] Unable to restart system
[   27.746845] Reboot failed -- System halted

Fixes: 8897f325

 ("arm64: dts: Add support for NXP LS1028A SoC")
Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>