CONFIG_SH_R7780RP is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

R7780RP-1 board support

modulename: irq-r7780rp.ko

configname: CONFIG_SH_R7780RP

Highlander options
└─>R7780RP-1 board support
In linux kernel since version 2.6.16 (release Date: 2006-03-19)  
source code:
arch/sh/boards/mach-highlander/irq-r7780rp.c