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

SNI RM200/300/400

modulename: fixup-sni.ko

configname: CONFIG_SNI_RM

System type
└─>SNI RM200/300/400
In linux kernel since version 2.6.20 (release Date: 2007-02-04)  
The SNI RM200/300/400 are MIPS-based machines manufactured by
Siemens Nixdorf Informationssysteme (SNI), parent company of Pyramid
Technology and now in turn merged with Fujitsu. Say Y here to
support this machine type.

source code:
arch/mips/pci/

is selected by
CONFIG_SERIAL_SC26XX