Roll buildroot to 2e0671b824e5

To pick up https://github.com/flutter/buildroot/pull/677

DEPS

diff --git a/DEPS b/DEPS
index 661b5cf..480abc0 100644
--- a/DEPS
+++ b/DEPS
@@ -239,7 +239,7 @@
 ]
 
 deps = {
-  'src': 'https://github.com/flutter/buildroot.git' + '@' + 'c77cac9502fb108be6a1ed4e0e4e1c65649b3a35',
+  'src': 'https://github.com/flutter/buildroot.git' + '@' + '2e0671b824e5228b1a8b6bed2fee41aebbb9b46b',
 
    # Fuchsia compatibility
    #