Revert "headers: Move IP_MREQ from _ip_mreq1.h to ws2ipdef.h."

This reverts commit 0c7108c439fcf349ec172843b022ccec5cef5da4
This revert fixes the build of SDL_net for x86 architecture.

Signed-off-by: Biswapriyo Nath <nathbappai@gmail.com>
Signed-off-by: Liu Hao <lh_mouse@126.com>
diff --git a/mingw-w64-headers/include/psdk_inc/_ip_mreq1.h b/mingw-w64-headers/include/psdk_inc/_ip_mreq1.h
index 5ca7bb3..1840ecb 100644
--- a/mingw-w64-headers/include/psdk_inc/_ip_mreq1.h
+++ b/mingw-w64-headers/include/psdk_inc/_ip_mreq1.h
@@ -4,9 +4,18 @@
  * No warranty is given; refer to the file DISCLAIMER.PD within this package.
  */
 
+/*
+ * Shared data types between winsock and winsock2
+ */
+
 #ifndef _MINGW_IP_MREQ1_H
 #define _MINGW_IP_MREQ1_H
 
 #include <inaddr.h>
 
+typedef struct ip_mreq {
+  struct in_addr imr_multiaddr;
+  struct in_addr imr_interface;
+} IP_MREQ, *PIP_MREQ;
+
 #endif	/* _MINGW_IP_MREQ1_H */
diff --git a/mingw-w64-headers/include/ws2ipdef.h b/mingw-w64-headers/include/ws2ipdef.h
index 188b2f4..d440bbc 100644
--- a/mingw-w64-headers/include/ws2ipdef.h
+++ b/mingw-w64-headers/include/ws2ipdef.h
@@ -192,11 +192,6 @@
   MCAST_EXCLUDE
 } MULTICAST_MODE_TYPE;
 
-typedef struct ip_mreq {
-  IN_ADDR imr_multiaddr;
-  IN_ADDR imr_interface;
-} IP_MREQ, *PIP_MREQ;
-
 typedef struct ip_mreq_source {
   IN_ADDR imr_multiaddr;
   IN_ADDR imr_sourceaddr;