[PATCHv4 1/5] net/lwip: add lwip-external submodule

[Maxim Uvarov]

This commit adds the lwip library as a git submodule. I think
there has to be advantages to compile lwip inside U-boot,
i.e. use the same compiler and flags as the main code.
One of them is LTO and the other is to enable additional debug
options for network protocol during development. Also we can
copy lwip library code inside U-boot, but for now I don't want
to send all lwip code to the mailing list. So it's git submodule.

Signed-off-by: Maxim Uvarov <maxim.uvarov at linaro.org>
---
 .gitmodules            | 3 +++
 lib/lwip/lwip-external | 1 +
 2 files changed, 4 insertions(+)
 create mode 100644 .gitmodules
 create mode 160000 lib/lwip/lwip-external

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000000..afc709af10
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "lib/lwip/lwip-external"]
+	path = lib/lwip/lwip-external
+	url = https://git.savannah.nongnu.org/git/lwip.git
diff --git a/lib/lwip/lwip-external b/lib/lwip/lwip-external
new file mode 160000
index 0000000000..3fe8d2fc43
--- /dev/null
+++ b/lib/lwip/lwip-external
@@ -0,0 +1 @@
+Subproject commit 3fe8d2fc43a9b69f7ed28c63d44a7744f9c0def9
-- 
2.30.2