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

CONFIG_IMX_HAVE_PLATFORM_GPIO_KEYS (not configurable)

modulename: platform-gpio_keys.ko

configname: CONFIG_IMX_HAVE_PLATFORM_GPIO_KEYS

Linux Kernel Configuration
└─>IMX_HAVE_PLATFORM_GPIO_KEYS
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
source code:
arch/arm/mach-imx/devices/platform-gpio_keys.c