dt-bindings: soc: add vf610 reboot syscon controller

dt-bindings: soc: add vf610 reboot syscon controller

Add vf610 reboot controller, which used to reboot whole system. Fix below
CHECK_DTB warnings:

arch/arm/boot/dts/nxp/vf/vf610-bk4.dtb: /soc/bus@40000000/src@4006e000:
    failed to match any schema with compatible: ['fsl,vf610-src', 'syscon']

IC reference manual calls it as system reset controller(SRC), but it is not
module as reset controller, which used to reset individual device. SRC
works as reboot controller, which reboots whole system. It provides a
syscon interface to syscon-reboot.

Signed-off-by: Frank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250819165317.3739366-1-Frank.Li@nxp.com
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>