Don't loop infinitely long on serial comm failures

If serial uart (8250/16x50) takes abnormally long to respond, give
up on logging to serial console and instead let the system boot.

Also reference bit in LSR register with correct name.

Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>

Ported from 9dd3ef165a1bf1bc404056d3e54337de1a15ac90 to
uart8250mem.c:
Signed-off-by: Stefan Reinauer <reinauer@google.com>

Change-Id: Iaca4f57389c887110e6406d45053935891c96838
Reviewed-on: http://review.coreboot.org/826
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Tested-by: build bot (Jenkins)
Reviewed-by: Peter Stuge <peter@stuge.se>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
1 file changed