boards: arm: update STM32H7B3I DK Kconfig

Update Kconfig to improve LVGL Demo performance.

- enable ICache,  DCache, and cache management.
- enable Chrom-ART.
- enable double frame buffer and full refresh.
- set bits per pixel to 16.

Signed-off-by: Charles Dias <charlesdias.cd@outlook.com>
5 files changed