[HELP] What interface should be used for LCD display in MIPS SOC?

### Description

I am working on running Nuttx-12.13.0 and lvgl in my MIPS SOC.
There is a display processing unit (DPU) in the SOC, which can drive TFT or RGB LCD displays.

I have ported the DPU driver into Nuttx and registered a `/dev/lcd0`, the performace of `lvgldemo "widgets"` is bad, its `FPS` is less than 10.

I tested the lower level driver codes with full screen of red and green, its `FPS` is about 30, so I think the lower driver is working fine.

I am not sure if I should use `framebuffer` interface with the DPU in my porting, and if so what is the good reference of framebuffer driver I can turn to?

Thanks,

### Verification

- [x] I have verified before submitting the report.

Start by reading the NuttX LCD and framebuffer interface documentation, focusing on how the registered /dev/lcd0 is consumed by LVGL. Compare the lvgldemo "widgets" FPS with the lower-level full-screen tests; the work is complete when the appropriate interface and likely performance bottleneck are documented.

Written by the indexing model from the issue text.