[component] Limit who can depend on lib/component/cpp

This library is being replaced by //sdk/lib/sys/cpp. This starts
limiting who can use the old library. As we migrate clients to the new
library, we can tighten down the broad allow patterns in this initial
list.

Change-Id: Ic1e5ca2097f7fd5da327fccb9f3cd1ad4526407b