wget is missing from some system (like macOS and Windows native),
it's better to use curl to simplify build environment.
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>
This makes LVGL use malloc/free to handle its memory (instead of
their own memory handling) and supports a tick interface by which
LVGL can ask NuttX the elapsed time, instead of having to periodically
"tick" LVGL internal time in a thread.
