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

HTC Dream (aka trout)

modulename: board-trout.ko

configname: CONFIG_MACH_TROUT

Linux Kernel Configuration
└─>Qualcomm MSM Board Type
└─>HTC Dream (aka trout)
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
Support for the HTC Dream, T-Mobile G1, Android ADP1 devices.

source code:
/arch/arm/mach-msm/