CONFIG_ETRAX_SERIAL_PORT1 is not available for thedefaultarchitecture x86.
Result is shown for architecture cris

Serial port 1 enabled

configname: CONFIG_ETRAX_SERIAL_PORT1

Linux Kernel Configuration
└─>Serial port 1 enabled
In linux kernel since version 2.6.12  
Enables the ETRAX FS serial driver for ser1 (ttyS1).