Add basics for a POCSAG Cal mode

MMDVM.ino

@@ -61,6 +61,7 @@ CCalDStarTX calDStarTX;
 CCalDMR     calDMR;
 CCalP25     calP25;
 CCalNXDN    calNXDN;
+CCalPOCSAG  calPOCSAG;
 CCalRSSI    calRSSI;
 
 CCWIdTX cwIdTX;
@@ -114,6 +115,9 @@ void loop()
   if (m_modemState == STATE_NXDNCAL1K)
     calNXDN.process();
 
+  if (m_modemState == STATE_POCSAGCAL)
+    calPOCSAG.process();
+
   if (m_modemState == STATE_IDLE)
     cwIdTX.process();
 }