soc/amd/picasso/uart: make index parameters unsigned

The UART index is never negative, so make it unsigned and drop the check
for the index to be non-negative.

BRANCH=zork

Change-Id: I38b5dad87f8af4fbe8ee1d919230efe48f68686c
Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45292
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>

0 files changed, 0 insertions, 0 deletions