default or selected kernelversion does not have config value CONFIG_INPUT_GP2A.
Result is shown for kernelversion 6.9.9

Sharp GP2AP002A00F I2C Proximity/Opto sensor driver

modulename: gp2ap002a00f.ko

configname: CONFIG_INPUT_GP2A

Linux Kernel Configuration
└─>Device Drivers
└─>Input device support
└─>Miscellaneous devices
└─>Sharp GP2AP002A00F I2C Proximity/Opto sensor driver
In linux kernel since version 3.1 (release Date: 2011-10-24)  
Say Y here if you have a Sharp GP2AP002A00F proximity/als combo-chip
hooked to an I2C bus.

To compile this driver as a module, choose M here: the
module will be called gp2ap002a00f.

source code:
depends
CONFIG_I2C
CONFIG_INPUT
CONFIG_INPUT_MISC
NOT CONFIG_UML
CONFIG_COMPILE_TEST or CONFIG_GPIOLIB