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

CONFIG_PM_RMOBILE (not configurable)

modulename: pm-rmobile.ko

configname: CONFIG_PM_RMOBILE

Linux Kernel Configuration
└─>PM_RMOBILE
In linux kernel since version 3.18 (release Date: 2014-12-07)  
source code:
arch/arm/mach-shmobile/pm-rmobile.c
selects
CONFIG_PM
CONFIG_PM_GENERIC_DOMAINS