Usually a device needs to be ported, ie the image needs to be tailored to your hardware (flash chip, amount of RAM, ...). You cannot just flash any image like you'd do with x86 hardware.
Your hardware looks like it could allow for OpenWrt support (enough flash and RAM) but you'd need to port it first afaik. Also keep in mind the modem part may not work, few DSL modems are supported by OpenWrt (blame the manufacturers).