Add first draft ethernet support

Author: dtwood

tm4c129x-hal/Cargo.toml

@@ -15,10 +15,15 @@ repository = "https://github.com/thejpster/tm4c-hal/tm4c129x-hal"
 edition = "2018"
 
 [dependencies]
+bare-metal = "0.2.4"
 cortex-m = "0.6"
 nb = "0.1"
 tm4c129x = "0.9"
 
+[dependencies.byteorder]
+version = "1"
+default-features = false
+
 [dependencies.cast]
 version = "0.2"
 default-features = false
@@ -27,6 +32,17 @@ default-features = false
 version = "0.2"
 features = ["unproven"]
 
+[dependencies.smoltcp]
+version = "0.6"
+default_features = false
+features = [
+    "proto-ipv4",
+    "proto-ipv6",
+    "socket-raw",
+    "socket-udp",
+    "socket-tcp",
+]
+
 [dependencies.void]
 version = "1.0"
 default-features = false
@@ -35,5 +51,9 @@ default-features = false
 version = "0.3.0"
 path = "../tm4c-hal"
 
+[dependencies.vcell]
+version = "0.1.0"
+features = ["const-fn"]
+
 [features]
 rt = ["tm4c129x/rt"]