upgrade vendored libxmp to latest 4.6.2 release

Author: sezero

.gitmodules

@@ -29,7 +29,7 @@
 [submodule "libxmp"]
 	path = external/libxmp
 	url = https://github.com/libsdl-org/libxmp.git
-	branch = 4.6.1-SDL
+	branch = 4.6.2-SDL
 [submodule "external/wavpack"]
 	path = external/wavpack
 	url = https://github.com/libsdl-org/wavpack.git

VisualC/external/include/xmp.h

@@ -9,11 +9,11 @@
 extern "C" {
 #endif
 
-#define XMP_VERSION "4.6.1"
-#define XMP_VERCODE 0x040601
+#define XMP_VERSION "4.6.2"
+#define XMP_VERCODE 0x040602
 #define XMP_VER_MAJOR 4
 #define XMP_VER_MINOR 6
-#define XMP_VER_RELEASE 1
+#define XMP_VER_RELEASE 2
 
 #if defined(_WIN32) && !defined(__CYGWIN__)
 # if defined(LIBXMP_STATIC)