x86: expose console_tx_flush in romstage
The vboot module relied on being able to flush the console
after it called vtxprintf() from its log wrapper function.
Expose the console_tx_flush() function in romstage so the
vboot module can ensure messages are flushed.
Change-Id: I578053df4b88c2068bd9cc90eea5573069a0a4e8
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/2882
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>