CONFIG_AT91_EARLY_USART3 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_AT91_EARLY_USART3.
Result is shown for kernelversion 6.2.5

USART3

configname: CONFIG_AT91_EARLY_USART3

Select a UART for early kernel messages
└─>USART3
In linux kernel since version 2.6.25 (release Date: 2008-04-16)