Update xbox 1

Makefile.libretro

@@ -424,6 +424,7 @@ TARGET := $(TARGET_NAME)_libretro_xdk1.lib
 MSVCBINDIRPREFIX = $(XDK)/xbox/bin/vc71
 CC  = "$(MSVCBINDIRPREFIX)/CL.exe"
 CXX  = "$(MSVCBINDIRPREFIX)/CL.exe"
+LD   = "$(MSVCBINDIRPREFIX)/lib.exe"
 
 PATH := $(shell IFS=$$'\n'; cygpath "$(MSVCBINDIRPREFIX)"):$(PATH)
 INCLUDE := $(shell IFS=$$'\n'; cygpath "$(VS71COMNTOOLS)../../Vc7/include")
@@ -569,7 +570,7 @@ ifneq (,$(findstring msvc,$(platform)))
 	OBJOUT = -Fo
 	LINKOUT = -out:
 ifeq ($(STATIC_LINKING),1)
-	LD = lib.exe
+	LD ?= lib.exe
 	STATIC_LINKING=0
 else
 	LD = link.exe