endian.h wasn't included (although it probably came in as an indirect
include) but in some header sets _XOPEN_SOURCE overrides _DEFAULT_SOURCE
whereas the latter is a super set of the former:
We should get the same things as with _XOPEN_SOURCE (such as memccpy for
which it has been defined) but also extra features like htole32.
Change-Id: Iaee7495b2ae64fdc719ae0879ea95fe7df286212
Signed-off-by: Patrick Georgi <patrick@coreboot.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/59891
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Rob Barnes <robbarnes@google.com>