default or selected kernelversion does not have config value CONFIG_FB_OMAP_CONSISTENT_DMA_SIZE.
Result is shown for kernelversion 6.2.5

Consistent DMA memory size (MB)

configname: CONFIG_FB_OMAP_CONSISTENT_DMA_SIZE

Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>Consistent DMA memory size (MB)
In linux kernel since version 2.6.24 (release Date: 2008-01-24)  
Increase the DMA consistent memory size according to your video
memory needs, for example if you want to use multiple planes.
The size must be 2MB aligned.
If unsure say 1.