mgcp_network: refactor MGCP_DUMMY_LOAD

The constant MGCP_DUMMY_LOAD is used ambigously. Sometimes it is used as
initalizer for an array, sometimes it is used as a single byte. Also the
name is not very expressive. Lets refactor this.

Change-Id: I21d96cefeeb647958bfa1e22a0ea030884746fad
Related: OS#4005
4 files changed