Revert "Remove hotplug from simpleramfs"

This reverts commit f3b254f2cb045a8ebe3dc01e8ead51ee26c88bd3.

Causes problems for spacecast. See discussion in b/34131115.

Change-Id: Ib760b8c7b2ba6294d918c7cb830004c27e7a5ad0
diff --git a/package/simpleramfs/simpleramfs.mk b/package/simpleramfs/simpleramfs.mk
index 3049a1e..154b965 100644
--- a/package/simpleramfs/simpleramfs.mk
+++ b/package/simpleramfs/simpleramfs.mk
@@ -104,6 +104,7 @@
 		$(@D)/fs/bin/
 
 	# driver firmware and modules
+	ln -f	fs/skeleton/sbin/hotplug $(@D)/fs/sbin/
 	ln -f	fs/skeleton/etc/utils.sh $(@D)/fs/etc/
 	if [ "$(BR2_PACKAGE_MINDSPEED_DRIVERS)" = "y" ]; then \
 		mkdir -p $(@D)/fs/lib/modules $(@D)/fs/lib/firmware && \