Add fsp_write_line function which may be called by FSP to output debug
serial data to the console.
TEST=Build and run on Galileo Gen2
Change-Id: Ib01aef448798e47ac613b38eb20bf25537b9221f
Signed-off-by: Lee Leahy <leroy.p.leahy@intel.com>
Reviewed-on: https://review.coreboot.org/16128
Tested-by: build bot (Jenkins)
Reviewed-by: Martin Roth <martinroth@google.com>