CONFIG_ARCH_DAVINCI_DM644x is not available for thedefaultarchitecture x86.
Result is shown for architecture arm
default or selected kernelversion does not have config value CONFIG_ARCH_DAVINCI_DM644x.
Result is shown for kernelversion 6.9.9

DaVinci 644x based system

modulename: dm644x.ko

and/or

pll-dm644x.ko

and/or

psc-dm644x.ko

configname: CONFIG_ARCH_DAVINCI_DM644x

Linux Kernel Configuration
└─>TI DaVinci
└─>DaVinci 644x based system
In linux kernel since version 2.6.30 (release Date: 2009-06-09)  
source code:
/arch/arm/mach-davinci/