CONFIG_ARCH_BCM is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
Broadcom SoC Support
configname: CONFIG_ARCH_BCM
Linux Kernel Configuration
└─>Broadcom SoC Support
In linux kernel since version 3.1 (release Date: 2011-10-24)
This enables support for Broadcom ARM based SoC chips