CONFIG_DA850_UI_RMII is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

RMII Ethernet PHY

configname: CONFIG_DA850_UI_RMII

Select peripherals connected to expander on UI board
└─>RMII Ethernet PHY
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Say Y if you want to use the RMII PHY on the DA850/OMAP-L138/AM18x
EVM. This PHY is found on the UI daughter card that is supplied with
the EVM.
NOTE: Please take care while choosing this option, MII PHY will
not be functional if RMII mode is selected.