CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc

RTAS Console

configname: CONFIG_PPC_EARLY_DEBUG_RTAS_CONSOLE

Early debugging console
└─>RTAS Console
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
Select this to enable early debugging via the RTAS console.