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

CONFIG_MACH_OMAP_GENERIC (not configurable)

modulename: board-generic.ko

configname: CONFIG_MACH_OMAP_GENERIC

Linux Kernel Configuration
└─>TI OMAP2/3/4 Specific Features
└─>MACH_OMAP_GENERIC
In linux kernel since version 2.6.12  
source code:
depends
CONFIG_ARCH_OMAP2PLUS or CONFIG_ARCH_OMAP1 |
| CONFIG_ARCH_OMAP15XX or CONFIG_ARCH_OMAP16XX

is depended by
CONFIG_SOC_AM43XX