linux: more networking features

The bridge support is gonna come handy for daisy-chaining :), and the
LED triggers are there just for prettiness. But who knows, perhaps we'll
add more LEDs to show the module state, eventually...

I'm also adding iproute2 for manual bridge management.

Change-Id: I6aa29ea53320b491e3b063325fd0723215d29305
diff --git a/configs/czechlight_clearfog_defconfig b/configs/czechlight_clearfog_defconfig
index 4306422..fe52f8d 100644
--- a/configs/czechlight_clearfog_defconfig
+++ b/configs/czechlight_clearfog_defconfig
@@ -33,6 +33,7 @@
 BR2_PACKAGE_SPI_TOOLS=y
 BR2_PACKAGE_UBOOT_TOOLS=y
 BR2_PACKAGE_LIBGPIOD_TOOLS=y
+BR2_PACKAGE_IPROUTE2=y
 BR2_PACKAGE_OPENSSH=y
 BR2_PACKAGE_BASH=y
 BR2_PACKAGE_INOTIFY_TOOLS=y