arm64: dts: fsl-ls1028a: add fsl,ls1028-reset for syscon

Add platform specific compatiable string 'fsl,ls1028-reset' for syscon and
move reboot node under reset syscon node to fix below warning.

syscon@1e60000: compatible: 'anyOf' conditional failed, one must be fixed:
        ['syscon'] is too short
        'syscon' is not one of ['al,alpine-sysfabric-service', ...

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>