Clean up phy_init_nr_gNB()

- variable is_secondary_gnb is not used anywhere, so remove
- variable lowmem is not used/defines should be changed, so remove

openair1/SIMULATION/NR_PHY/dlschsim.c

@@ -366,7 +366,7 @@ int main(int argc, char **argv)
 	frame_parms->Ncp = extended_prefix_flag ? EXTENDED : NORMAL;
 	crcTableInit();
 	nr_phy_config_request_sim(gNB, N_RB_DL, N_RB_DL, mu, Nid_cell,SSB_positions);
-	phy_init_nr_gNB(gNB, 0, 1); //lowmem
+	phy_init_nr_gNB(gNB);
 	//init_eNB_afterRU();
 	frame_length_complex_samples = frame_parms->samples_per_subframe;
 	//frame_length_complex_samples_no_prefix = frame_parms->samples_per_subframe_wCP;