Fix 'make distcheck' for hw/xwin

Add some missing header files to _SOURCES so they get distributed properly

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Reviewed-by: Yaakov Selkowitz <yselkowitz@users.sourceforge.net>

hw/xwin/Makefile.am

@@ -109,13 +109,16 @@ SRCS =	InitInput.c \
 	winclipboard.h \
 	winconfig.h \
 	win.h \
+	winglobals.h \
 	winkeybd.h \
 	winkeynames.h \
 	winlayouts.h \
 	winmessages.h \
+	winmonitors.h \
 	winmsg.h \
 	winms.h \
 	winmultiwindowclass.h \
+	winmultiwindowicons.h \
 	winprefs.h \
 	winresource.h \
 	winwindow.h \

hw/xwin/glx/Makefile.am

@@ -6,7 +6,8 @@ libXwinGLX_la_SOURCES = \
 	glwindows.h \
 	glwrap.c \
 	indirect.c \
-	wgl_ext_api.c
+	wgl_ext_api.c \
+	wgl_ext_api.h
 
 if XWIN_MULTIWINDOW
 DEFS_MULTIWINDOW = -DXWIN_MULTIWINDOW