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

Enable Sharp SL-6000x (Tosa) Support

modulename: tosa.ko

configname: CONFIG_MACH_TOSA

Linux Kernel Configuration
└─>PXA2xx/PXA3xx-based
└─>Intel PXA2xx/PXA3xx Implementations
└─>Enable Sharp SL-6000x (Tosa) Support
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
source code:
arch/arm/mach-pxa/tosa.c
selects
CONFIG_PXA25x