Downgrade gNB power limit LOG from "warning" to "debug"

Downgrade the UE power limited LOG from LOG_W to LOG_D. This is to avoid flooding
stdout when UE in low coverage enters power limited state for a longer period of
time. The same information can be inferred from the periodic UE print which also
contains PH value (negative PH values indicate that the UE is power limited)

openair2/LAYER2/NR_MAC_gNB/gNB_scheduler_ulsch.c

@@ -1641,7 +1641,7 @@ static void nr_ue_max_mcs_min_rb(int mu,
   }
 
   if (ph_limit < tx_power)
-    LOG_W(NR_MAC, "Normalized power %d based on current resources (RBs %d, MCS %d) exceed reported PHR %d (normalized value)\n",
+    LOG_D(NR_MAC, "Normalized power %d based on current resources (RBs %d, MCS %d) exceed reported PHR %d (normalized value)\n",
           tx_power, *Rb, *mcs, ph_limit);
 }