CONFIG_BCM47XX_BCMA is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

BCMA Support for Broadcom BCM47XX

configname: CONFIG_BCM47XX_BCMA

Linux Kernel Configuration
└─>BCMA Support for Broadcom BCM47XX
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Add support for new Broadcom BCM47xx boards with Broadcom specific Advanced Microcontroller Bus.

This will generate an image with support for BCMA and MIPS32 R2 instruction set.