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

CONFIG_IMX_HAVE_PLATFORM_MXC_RTC (not configurable)

modulename: platform-mxc_rtc.ko

configname: CONFIG_IMX_HAVE_PLATFORM_MXC_RTC

Linux Kernel Configuration
└─>IMX_HAVE_PLATFORM_MXC_RTC
In linux kernel since version 3 (release Date: 2011-07-21)  
source code:
arch/arm/plat-mxc/devices/platform-mxc_rtc.c