CONFIG_MACH_RX3715 is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

HP iPAQ rx3715

modulename: mach-rx3715.ko

configname: CONFIG_MACH_RX3715

Linux Kernel Configuration
└─>S3C2440 Machines
└─>HP iPAQ rx3715
In linux kernel since version 2.6.12  
Say Y here if you are using the HP iPAQ rx3715.

source code: