CONFIG_CPU_SUBTYPE_SH7786 is not available for thedefaultarchitecture x86.
Result is shown for architecture sh

Support SH7786 processor

modulename: pcie-sh7786.ko

and/or

setup-sh7786.ko

configname: CONFIG_CPU_SUBTYPE_SH7786

Processor sub-type selection
└─>Support SH7786 processor
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
source code:
/arch/sh/drivers/pci/

is selected by
CONFIG_PINCTRL_PFC_SH7786