Remove FHI72 memory workaround

The queue L1_rx_out was in place to keep RX/TX processing relatively
"close" to each other (in terms of time, since in RFsim, they might
advance faster than realtime; see also parent commit). This lead to a
memory leak in radios that do not use ru->feprx (no front-end processing
for RX, e.g., PRACH), as the code to read the L1_rx_out messages was
inside a block of if (ru->feprx). Move it out so that the queue is
always read and messages are freed to eliminate the memory leak, and
remove the workaround for FHI72 to avoid this memory leak.

This also allows to run RFsim when compiling FHI72, which was not
possible before this commit.

Closes: #812

radio/fhi_72/CMakeLists.txt

@@ -43,6 +43,3 @@ set_target_properties(oran_fhlib_5g PROPERTIES LIBRARY_OUTPUT_DIRECTORY ${CMAKE_
 add_custom_command(TARGET oran_fhlib_5g POST_BUILD
                    COMMAND ${CMAKE_COMMAND} -E create_symlink liboran_fhlib_5g.so liboai_transpro.so
                    WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
-
-message(STATUS "Temporary added -DOAI_FHI72")
-target_compile_definitions(nr-softmodem PUBLIC OAI_FHI72)