Add HOST_CROSS_OS

Instead of using recursive make to change the HOST_OS when building the
windows SDK under linux, add the concept of cross-building to another
host os.

Bug: 23566667
Change-Id: I6dc525b601b6251d458d197c30bf4660d7485502
diff --git a/core/notice_files.mk b/core/notice_files.mk
index 43a5435..cf2dad6 100644
--- a/core/notice_files.mk
+++ b/core/notice_files.mk
@@ -14,6 +14,7 @@
 # so my_prefix is not set at this point.
 ifeq ($(LOCAL_IS_HOST_MODULE),true)
   my_prefix := HOST_
+  LOCAL_HOST_PREFIX :=
 else
   my_prefix := TARGET_
 endif
@@ -56,6 +57,7 @@
 
 # In case it's actually a host file
 module_installed_filename := $(patsubst $(HOST_OUT)%,%,$(module_installed_filename))
+module_installed_filename := $(patsubst $(HOST_CROSS_OUT)%,%,$(module_installed_filename))
 
 installed_notice_file := $($(my_prefix)OUT_NOTICE_FILES)/src/$(module_installed_filename).txt