CONFIG_INPUT is not available for thedefaultarchitecture x86.
Result is shown for architecture um

CONFIG_INPUT (not configurable)

modulename: input.ko

configname: CONFIG_INPUT

Linux/Usermode Kernel Configuration
└─>INPUT
In linux kernel since version 2.6.12  
source code:
drivers/input/input.c
is depended by
CONFIG_BT_HIDP