CONFIG_ARCH_IXDP2801 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Support Intel IXDP2801 and IXDP28x5
configname: CONFIG_ARCH_IXDP2801
Linux Kernel Configuration
└─>Intel IXP2400/2800 Implementation Options
└─>Support Intel IXDP2801 and IXDP28x5
In linux kernel since version 2.6.12
Say 'Y' here if you want your kernel to support the Intel
IXDP2801/2805/2855 reference platforms. For more information on
this platform, see Documentation/arm/IXP2000.
IXDP2801/2805/2855 reference platforms. For more information on
this platform, see Documentation/arm/IXP2000.