Move serial.c into drivers/serial-s3c24xx.c and qi-serial.h into include/serial-s3c24xx.h
making things a bit cleaner for being s3c24xx-specific. This needed a lot of meddling
additionally, ending up with a new puts() callback that belongs in the board structure
and removal of the debug uart member, since the puts() action was the only user.
Also change serial init API name and function to only fix to 115kbps and adapt to
PCLK.
Signed-off-by: Andy Green <andy@openmoko.com>