Support LVGL 9 on Round Display

[Timo614]

Ran into two issues:

• The tick logic has changed in LVGL 9 such that you need to specify the tick callback vs the ENV var so I persisted the LVGL 8 env vars in the config for backwards compatibility but added some custom logic to the example such that it runs that (was unable to use the touch screen prior) lvgl/lvgl@0b83a82#diff-7c9693e9c5e61a1d80e09769377d47bb415ec39ca5aeaa85d13581b0105d6359L138-L145
• On the RP2040 I was unable to render a display on the screen until I updated the buffer to the uint32_t type.

:cpp:func:lv_display_set_buffers(display, buf1, buf2, buf_size_byte, mode) is more or less the equivalent of lv_disp_draw_buf_init(&draw_buf_dsc, buf1, buf2, buf_size_px) from v8, however in v9 the buffer size is set in bytes.

I took the config for lvgl 9.1 and updated it to reflect the shared env vars. Not sure if having separate configs would be a better approach here though.

I'll test this out further tomorrow on the other Xiao boards to confirm everything is still functioning and in good order.

[Timo614]

Having trouble with the Xiao ESP boards and this branch so should hold for merging for now until they are confirmed to be working fully.