[XL] Change in coreboot[main]: lib/device_tree: Add some FDT helper functions

[Maximilian Brune (Code Review)]

Attention is currently required from: Jakub Czapiga, Martin L Roth, Maximilian Brune.

Hello Jakub Czapiga, Julius Werner, Martin L Roth, build bot (Jenkins),

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

https://review.coreboot.org/c/coreboot/+/81081?usp=email

to look at the new patch set (#17).

The following approvals got outdated and were removed:
Verified-1 by build bot (Jenkins)

Change subject: lib/device_tree: Add some FDT helper functions
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lib/device_tree: Add some FDT helper functions

This adds some helper functions for FDT, since more and more mainboards
seem to need FDT nowadays. For example our QEMU boards need it in order
to know how much RAM is available. Also all RISC-V boards in our tree
need FDT.

This also adds some tests in order to test said functions.

Signed-off-by: Maximilian Brune 
Change-Id: I2fb1d93c5b3e1cb2f7d9584db52bbce3767b63d8
---
M src/include/device_tree.h
M src/lib/device_tree.c
M tests/lib/Makefile.mk
A tests/lib/device_tree-test.c
A tests/lib/tegra30-ouya.dtb.xxd
A tests/lib/virt.dtb.xxd
M util/lint/lint-000-license-headers
7 files changed, 14,250 insertions(+), 47 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/81/81081/17