usbdebug: Unify console API

Struct dbgp_pipe would not be suitable for use with xHCI.
Just use an index, it is easy to setup in Kconfig if our
future debug setup has separate pipes for console
output and debugging/traceings.

Change-Id: Icbbd28f03113b208016f80217ab801d598d443a8
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/5227
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>
5 files changed