libpayload: Add timeouts in the UHCI USB driver

We should always have some timeout when we wait for the hardware. This adds
missing timeouts to the UHCI driver.

Change-Id: Ic37b95ce12ff3ff5efe3e7ca346090946f6ee7de
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/1073
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <patrick@georgi-clan.de>
2 files changed