CONFIG_ARCH_LPC32XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

NXP LPC32XX

modulename: irq-lpc32xx.ko

and/or

clk-lpc32xx.ko

configname: CONFIG_ARCH_LPC32XX

Linux Kernel Configuration
└─>NXP LPC32XX
In linux kernel since version 2.6.36 (release Date: 2010-10-20)  
Support for the NXP LPC32XX family of processors

source code:
drivers/irqchip/irq-lpc32xx.c