default or selected kernelversion does not have config value CONFIG_OMAP2_VRAM_SIZE.
Result is shown for kernelversion 6.2.5

VRAM size (MB)


Linux Kernel Configuration
└─>Device Drivers
└─>Graphics support
└─>OMAP2+ Display Subsystem support (EXPERIMENTAL)
└─>VRAM size (MB)
In linux kernel since version 2.6.33 (release Date: 2010-02-24)  
The amount of SDRAM to reserve at boot time for video RAM use.
This VRAM will be used by omapfb and other drivers that need
large continuous RAM area for video use.

You can also set this with "vram=<bytes>" kernel argument, or
in the board file.