Add missing init module

lib/farmbot/system/init/kernel_mods.ex

@@ -0,0 +1,21 @@
+defmodule Farmbot.System.Init.KernelMods do
+  use Supervisor
+  use Farmbot.Logger
+  @mods Application.get_env(:farmbot, :kernel_modules, [])
+
+  def start_link(_, opts \\ []) do
+    Supervisor.start_link(__MODULE__, [], opts)
+  end
+
+  def init([]) do
+    do_checkup()
+    :ignore
+  end
+
+  defp do_checkup do
+    for mod <- @mods do
+      Logger.info 1, "Loading kernel module: #{mod}"
+      System.cmd "modprobe", [mod], into: IO.stream(:stdio, :line)
+    end
+  end
+end