CONFIG_BCM63XX_CPU_6328 is not available for thedefaultarchitecture x86.
Result is shown for architecture mips

support 6328 CPU

configname: CONFIG_BCM63XX_CPU_6328

Linux Kernel Configuration
└─>CPU support
└─>support 6328 CPU
In linux kernel since version 3.1 (release Date: 2011-10-24)  

depends
CONFIG_BCM63XX