(Almost) Remove all PHY/phy_vars* and PHY/phy_extern

doc/Doxyfile

executables/lte-ru.c

executables/main_ru.c

openair1/PHY/INIT/lte_init_ru.c

openair1/PHY/INIT/nr_init_ru.c

openair1/PHY/LTE_ESTIMATION/lte_sync_time.c

openair1/PHY/LTE_ESTIMATION/lte_sync_timefreq.c

openair1/PHY/LTE_ESTIMATION/lte_ue_measurements.c

openair1/PHY/LTE_ESTIMATION/lte_ul_channel_estimation.c

openair1/PHY/LTE_REFSIG/README.txt

openair1/PHY/LTE_REFSIG/primary_synch.h

openair1/PHY/LTE_TRANSPORT/dlsch_scrambling.c

openair1/PHY/LTE_TRANSPORT/dlsch_tbs.h

openair1/PHY/LTE_TRANSPORT/print_stats.c

openair1/PHY/LTE_TRANSPORT/pss.c

openair1/PHY/LTE_TRANSPORT/ulsch_demodulation.c

openair1/PHY/LTE_UE_TRANSPORT/dci_tools_ue.c

openair1/PHY/LTE_UE_TRANSPORT/dlsch_demodulation.c

openair1/PHY/LTE_UE_TRANSPORT/pbch_ue.c

openair1/PHY/LTE_UE_TRANSPORT/pmch_ue.c