CONFIG_ALPHA is not available for thedefaultarchitecture x86.
Result is shown for architecture alpha

CONFIG_ALPHA (not configurable)

modulename: setup-bus.ko

configname: CONFIG_ALPHA

Linux Kernel Configuration
└─>ALPHA
In linux kernel since version 2.6.12  
The Alpha is a 64-bit general-purpose processor designed and
marketed by the Digital Equipment Corporation of blessed memory,
now Hewlett-Packard. The Alpha Linux project has a home page at
<http://www.alphalinux.org/>.

source code:
selects
CONFIG_HAVE_AOUT
CONFIG_HAVE_IDE
CONFIG_HAVE_OPROFILE
CONFIG_HAVE_SYSCALL_WRAPPERS
CONFIG_HAVE_IRQ_WORK
CONFIG_HAVE_PERF_EVENTS
CONFIG_HAVE_DMA_ATTRS
CONFIG_HAVE_GENERIC_HARDIRQS
CONFIG_GENERIC_IRQ_PROBE
CONFIG_AUTO_IRQ_AFFINITY
CONFIG_GENERIC_IRQ_SHOW
CONFIG_ARCH_WANT_OPTIONAL_GPIOLIB

is selected by
CONFIG_FB_TGA