trx: renaming of old freq hopping block and creation of a new one

The old freq_hopper -controlling USRP frequency with use of tags -
was renamed to freq_hopper_tag. The new one - freq_hopper_msg -  that
uses uhd_source or uhd_sink control message input was created.

Change-Id: Ic867446314ef2ee6903cef85d48c280981132dae
diff --git a/lib/trx/CMakeLists.txt b/lib/trx/CMakeLists.txt
index 0bfbe34..cd8f556 100644
--- a/lib/trx/CMakeLists.txt
+++ b/lib/trx/CMakeLists.txt
@@ -19,6 +19,7 @@
 
 add_sources(
     trx_burst_if_impl.cc
-    freq_hopping_impl.cc
+    freq_hopper_tag_impl.cc
+    freq_hopper_msg_impl.cc
 )