CONFIG_HAVE_AT91_GENERATED_CLK is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

CONFIG_HAVE_AT91_GENERATED_CLK (not configurable)

modulename: clk-generated.ko

configname: CONFIG_HAVE_AT91_GENERATED_CLK

Linux Kernel Configuration
└─>AT91/Microchip SoCs
└─>HAVE_AT91_GENERATED_CLK
In linux kernel since version 3.10 (release Date: 2013-06-30)  
source code:
drivers/clk/at91/clk-generated.c