display_rotate deprecated

[hhromic]

Hi, not sure if you are still maintaining this repository, hopefully you do :).

In recent firmware versions, the display_rotate variable has been deprecated in favour of the display_hdmi_rotate and display_lcd_rotate separate variables. See here:
https://www.raspberrypi.org/documentation/configuration/config-txt/video.md

This repository is used by the meta-raspberrypi Yocto BSP layer. It is possible to update your config.txt file to reflect this and keep up-to-date? Thanks!