This adds the following commits from upstream:

f267e674d145 checks: Fix crash with multiple source annotations
3616b9a811b6 checks: Use source position information for check failures
2bdbd07a1223 checks: Make each message output atomic
a1eff70c02cf util: Add xa{v}sprintf_append functions
82a52ce4573b libfdt: Add a test for fdt_getprop_by_offset()
607b8586b383 PEP8 / Flake8 cleanups for setup.py
f9c0a425b648 Remove broken objdir / srcdir support
5182b5e6f28c pylibfdt: Use common PREFIX variable
d45bf1f5f2a6 Refine make tests_clean target
99284c4db9cb Refine pylibfdt_clean target
a4629cfaedfb Refine libfdt_clean target
08380fc43aa2 tests: Use modern octal literals for Python
8113c00b99d3 pylibfdt: Allow switch to Python 3 via environment variable PYTHON
11738cf01f15 libfdt: Don't use memcpy to handle unaligned reads on ARM
86a288a73670 checks: Restructure check_msg to decrease indentation
5667e7ef9a9a annotations: add the annotation functionality
8e20ccf52f90 annotations: add positions
ca930e20bb54 tests: Don't lose errors from make checkm
43366bb4eeee tests: Property count valgrind errors in wrapped tests
5062516fb8cb srcpos: Remove srcpos_empty
a3143fafbf83 Revert "annotations: add positions"
403cc79f06a1 checks: Update SPI bus check for 'spi-slave'
baa1d2cf7894 annotations: add positions
ff2ad38f6a5a Merge remote-tracking branch 'origin/pr/18'
aa7254d9cb17 libfdt: return correct value if #size-cells property is not present
49903aed7783 use ptrdiff_t modifier for printing pointer differences
da2b691ccf68 treesource: Fix dts output for phandles in middle of a sequence of ints
8f8b77a0d62d tests: Wrap check_align() calls with base_run_test()
522d81d572f2 Fix dts output with a REF_PATH marker
e45198c98359 Added test cases for target references
0fcffda15e9f Merge nodes with local target label references
1e4a0928f3b3 pylibfdt: Don't have setup.py depend on where it's invoked from
ca399b14956f pylibfdt: Eliminate run_setup make function
98972f1b3e33 pylibfdt: Improved version extraction
7ba2be6cda5f pylibfdt: Don't silence setup.py when V=1
7691f9d39301 pylibfdt: Make SETUP make variable
855b9963def9 pylibfdt: Simpler CFLAGS handling
47cafbeeb977 pylibfdt: Link extension module with libfdt rather than rebuilding
dd695d6afb19 pylibfdt: Correctly set build output directory
59327523d0d8 pylibfdt: We don't need include files from the base directory
e84742aa7b93 checks: fix simple-bus compatible matching
8c59a97ce096 Fix missing labels when emitting dts format
d448f9a5fd94 Revert dts output formatting changes of spaces around brackets
Signed-off-by: Rob Herring <robh@kernel.org>