Logo is displayed by Linux kernel:
https://www.digi.com/resources/documentation/digidocs/90002285/#reference/bsp/v4-9_6ul/r_video_6ul.htm
Kernel configuration
You can manage the video support through the following kernel configuration options:
MXS LCD framebuffer support (CONFIG_FB_MXS)
Support for frame buffer devices (CONFIG_FB)
Low-level LCD controls (LCD_CLASS_DEVICE)
Platform LCD controls (LCD_PLATFORM)
Show the logo centered in the screen (FB_LOGO_CENTERED)
Custom logo 224-color (displays logo_custom_clut224.ppm) (LOGO_CUSTOM_CLUT224)
MXC PxP V4L2 driver (CONFIG_VIDEO_MXC_PXP_V4L2)