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

CONFIG_IRAM_ALLOC (not configurable)

modulename: iram_alloc.ko

configname: CONFIG_IRAM_ALLOC

Linux Kernel Configuration
└─>IRAM_ALLOC
In linux kernel since version 2.6.37 (release Date: 2011-01-04)  
source code:
arch/arm/plat-mxc/iram_alloc.c

depends
CONFIG_ARCH_MXC