srsue,rrc_nr: fix warning and error logs in SA mode

- provide PHY config state to configure MIB values (coreset0).
- set PRACH freq_offset to valid value to please config checker.

Addresses:
2022-04-19T12:42:38.726040 [PHY-SA ] [E] [    0] prach_cfg.freq_offset=0 is not compatible with LTE
2022-04-19T12:42:38.726040 [PHY-SA ] [I] [    0] PHY:   Set TA offset: n_ta_offset: 0, ta_usec: 0.0
2022-04-19T12:42:38.726141 [RRC-NR ] [W] PHY configuration completed without a clear state.

srsue/hdr/stack/rrc_nr/rrc_nr.h

@@ -201,6 +201,7 @@ private:
   // Stores the state of the PHY configuration setting
   enum {
     PHY_CFG_STATE_NONE = 0,
+    PHY_CFG_STATE_SA_MIB_CFG,
     PHY_CFG_STATE_SA_SIB_CFG,
     PHY_CFG_STATE_SA_FULL_CFG,
     PHY_CFG_STATE_NSA_APPLY_SP_CELL,

srsue/src/stack/rrc_nr/rrc_nr.cc

@@ -2225,6 +2225,9 @@ void rrc_nr::set_phy_config_complete(bool status)
     case PHY_CFG_STATE_NONE:
       logger.warning("PHY configuration completed without a clear state.");
       break;
+    case PHY_CFG_STATE_SA_MIB_CFG:
+      logger.info("PHY configuration with MIB parameters completed.");
+      break;
     case PHY_CFG_STATE_SA_SIB_CFG:
       logger.info("PHY configuration with SIB parameters completed.");
       break;

srsue/src/stack/rrc_nr/rrc_nr_procedures.cc

@@ -474,7 +474,11 @@ rrc_nr::cell_selection_proc::handle_cell_search_result(const rrc_interface_phy_n
   make_phy_search_space0_cfg(&phy_cfg.pdcch.search_space[0]);
   phy_cfg.pdcch.search_space_present[0] = true;
 
+  // Set dummy offset to pass PRACH config check, real value is provided in SIB1
+  phy_cfg.prach.freq_offset = 1;
+
   // Update PHY configuration
+  rrc_handle.phy_cfg_state = PHY_CFG_STATE_SA_MIB_CFG;
   if (not rrc_handle.phy->set_config(phy_cfg)) {
     Error("Setting PHY configuration");
     return proc_outcome_t::error;