Add RIL_UNSOL_OEM_HOOK_RAW

Add RIL_UNSOL_OEM_HOOK_RAW to send unsolicited OEM
commands from the baseband.

Tested using radiooptions tool.
diff --git a/libril/ril.cpp b/libril/ril.cpp
index b5749c3..54ee61f 100644
--- a/libril/ril.cpp
+++ b/libril/ril.cpp
@@ -2757,6 +2757,7 @@
         case RIL_UNSOL_RESPONSE_CDMA_NEW_SMS: return "UNSOL_NEW_CDMA_SMS";
         case RIL_UNSOL_RESPONSE_NEW_BROADCAST_SMS: return "UNSOL_NEW_BROADCAST_SMS";
         case RIL_UNSOL_CDMA_RUIM_SMS_STORAGE_FULL: return "UNSOL_CDMA_RUIM_SMS_STORAGE_FULL";
+        case RIL_UNSOL_OEM_HOOK_RAW: return "UNSOL_OEM_HOOK_RAW";
         default: return "<unknown request>";
     }
 }