CONFIG_ETRAX_WATCHDOG is not available for thedefaultarchitecture x86.
Result is shown for architecture cris

Enable ETRAX watchdog

configname: CONFIG_ETRAX_WATCHDOG

Linux Kernel Configuration
└─>General setup
└─>Enable ETRAX watchdog
In linux kernel since version 2.6.12  
Enable the built-in watchdog timer support on ETRAX based embedded
network computers.