csiim_vars/csirs_vars used to be global array for each UE. Now its present
in phy_data which is in dynamically allocated memory.
MAC config was done without mutex while DL and UL threads could be running
at the same time.
get_ue_nas_info was allocating memory possibly from more than one thread.
Moved it into new init function for UE NAS layer.
Addreses most issues in #869