FM: Add support to receive RT+ ,ECC events

This adds configuring RDS group processing for RT+ and ECC events,
Also includes code cleanup and changes to set proper value for RDS
group processing registers during SCREEN turn on after LOW Power
mode.

Change-Id: I1a6a5ce43a855cde1e32cc5e2d3bb03fe0af2625
diff --git a/helium/radio-helium.h b/helium/radio-helium.h
index cb85bcc..430ddbf 100644
--- a/helium/radio-helium.h
+++ b/helium/radio-helium.h
@@ -481,6 +481,8 @@
 #define HCI_EV_SEARCH_COMPLETE          0x12
 #define HCI_EV_SEARCH_RDS_COMPLETE      0x13
 #define HCI_EV_SEARCH_LIST_COMPLETE     0x14
+#define HCI_EV_RADIO_TEXT_PLUS_ID       0x18
+#define HCI_EV_RADIO_TEXT_PLUS_TAG      0x19
 
 #define HCI_REQ_DONE      0
 #define HCI_REQ_PEND      1