Add libfdt external component

Create external component to download the libfdt sources. After download
libfdt is patched to enable using libfdt's implementation of strnlen().
This is necessary because newlib doesn't export strnlen() for ISO C
sources (we build SPs as ISO C99).

Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Change-Id: Iac5fc19086c57aee409d2c0661cb498713b750e5
2 files changed