Change in coreboot[master]: lib/future: Implement Futures API

[Raul Rangel (Code Review)]

Attention is currently required from: Aaron Durbin, Martin Roth, Furquan Shaikh, Marshall Dawson, Julius Werner, Eric Peers.
Hello build bot (Jenkins), Aaron Durbin, Furquan Shaikh, Marshall Dawson, Julius Werner,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/coreboot/+/56048

to look at the new patch set (#4).

Change subject: lib/future: Implement Futures API
......................................................................

lib/future: Implement Futures API

This is implemented in coreboot instead of commonlib because commonlib
doesn't have things like printk, die and stopwatch.

A later CL will add calls to poll_futures to hardwaremain.c.

BUG=b:177909625
TEST=boot guybrush and see payload read/decompress time drop 23ms.

Signed-off-by: Raul E Rangel 
Change-Id: I350aebcd07024a00b90495bf937f8bca5193d02f
---
M src/lib/Kconfig
M src/lib/Makefile.inc
A src/lib/future.c
3 files changed, 142 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/48/56048/4