[enum types] add *_RESERVED = 0 entries

eliminate warnings with initializing a struct with = { 0 } due to enum
members that do not define the value 0

include/freerdp/autodetect.h

@@ -40,6 +40,7 @@ extern "C"
 
 	typedef enum
 	{
+		RDP_NETCHAR_RESERVED = 0x0000U,
 		/* The baseRTT and averageRTT fields are valid */
 		RDP_NETCHAR_RESULT_TYPE_BASE_RTT_AVG_RTT = 0x0840U,
 		/* The bandwidth and averageRTT fields are valid */

include/freerdp/channels/location.h

@@ -33,6 +33,7 @@ extern "C"
 
 	typedef enum
 	{
+		PDUTYPE_LOC_RESERVED = 0x0000,
 		PDUTYPE_SERVER_READY = 0x0001,
 		PDUTYPE_CLIENT_READY = 0x0002,
 		PDUTYPE_BASE_LOCATION3D = 0x0003,

include/freerdp/channels/rdpemsc.h

@@ -34,6 +34,7 @@ extern "C"
 
 	typedef enum
 	{
+		PDUTYPE_EMSC_RESERVED = 0x00,
 		PDUTYPE_CS_CAPS_ADVERTISE = 0x01,
 		PDUTYPE_SC_CAPS_CONFIRM = 0x02,
 		PDUTYPE_SC_MOUSEPTR_UPDATE = 0x03,