Some compiler is brain-damaged that it will yeild a warning for headers
not ended with a newline. Yes, I mean you, Keil.

M0 core is always booted by the M4 core. It means that if we are running
in M0, the clock is always configured.

Misc fix

Commit a6251a43 changed the serial device to check open_flag
instead of flag. So we should change the rt_kprintf counterpart as well.

fix stm32f407 uart3 TX config error

external: update freetype to 2.5.4

ymodem: fix a race-condition in handshaking

As we are sending C continuously, there is a chance that the
sender(remote) receive an C after sending the first handshake package.
So the sender will interpret it as NAK and re-send the package. So we
just ignore it and proceed.

lodepng: make the crc32 LUT const

This saves 1KiB ram usage.

Misc fix

RT_TIMER_TICK_PER_SECOND in rtconfig.h for softtime scheduler is not used.

Rt thread coing

Conflicts:
	bsp/lpc5410x/project.uvprojx

Before the project was established with RB_ROOT