CONFIG_OMAP_MCBSP is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

McBSP support

configname: CONFIG_OMAP_MCBSP

Linux Kernel Configuration
└─>TI OMAP Implementations
└─>McBSP support
In linux kernel since version 2.6.22 (release Date: 2007-07-08)  
Say Y here if you want support for the OMAP Multichannel
Buffered Serial Port.