mman-win32: remove obsolete patch

-package switched to cmake in ca5bba63 so patch has no effect
-header name doesn't seem to cause issues
-closes #1337

src/mman-win32-1-include_name_change.patch

@@ -1,14 +0,0 @@
-This file is part of MXE. See LICENSE.md for licensing information.
-
-diff -urN mman-win32-master/Makefile mman-win32-master-patch/Makefile
---- mman-win32-master/Makefile	2013-04-23 07:36:23.000000000 +0300
-+++ mman-win32-master-patch/Makefile	2014-01-05 14:24:31.793744239 +0200
-@@ -25,7 +25,7 @@
- 	mkdir -p $(DESTDIR)$(libdir)
- 	cp libmman.a $(DESTDIR)$(libdir)
- 	mkdir -p $(DESTDIR)$(incdir)
--	cp mman.h $(DESTDIR)$(incdir)
-+	cp mman.h $(DESTDIR)$(incdir)/mman-win32.h
- 
- lib-install:
- 	mkdir -p $(DESTDIR)$(libdir)