CONFIG_MCA is not available for thedefaultarchitecture x86.
Result is shown for architecture powerpc
default or selected kernelversion does not have config value CONFIG_MCA.
Result is shown for kernelversion 6.9.9

CONFIG_MCA (not configurable)

configname: CONFIG_MCA

Linux Kernel Configuration
└─>Bus options
└─>MCA
In linux kernel since version 2.6.12  
is selected by
CONFIG_SCSI_SIM710