com ports found on Intel PXA2x0 processors.
Re-arrange the code which detects the FIFO configuration to defer
printing until _after_ com_fifo is cleared. Some supposedly compatible
chips clear the Tx/Rx FIFOs when this happens, resulting in previous
output being lost.
Dave Huang <khym@bga.com>, with added check for broken early versions
of the 16650, taken from the Linux driver.
This should be extended to use, for example, higher trigger levels for
the bigger 16650 FIFO, and its capability for using a smaller divisor
and thus higher speeds. But this patch is very useful for 16650 users
already.