CONFIG_ARCH_OMAP16XX is not available for thedefaultarchitecture x86.
Result is shown for architecture arm

OMAP16xx Based System

modulename: gpio16xx.ko

and/or

ocpi.ko

configname: CONFIG_ARCH_OMAP16XX

Linux Kernel Configuration
└─>TI OMAP1 specific features
└─>OMAP16xx Based System
In linux kernel since version 2.6.12  
source code:
arch/arm/mach-omap1/gpio16xx.c


is selected by
CONFIG_RTC_DRV_OMAP