Define KAFFINITY.

diff --git a/include/basetsd.h b/include/basetsd.h
index bb6f9be..987d843 100644
--- a/include/basetsd.h
+++ b/include/basetsd.h
@@ -139,6 +139,8 @@
 typedef LONG_PTR SSIZE_T, *PSSIZE_T;
 typedef ULONG_PTR SIZE_T, *PSIZE_T;
 
+typedef ULONG_PTR KAFFINITY, *PKAFFINITY;
+
 /* Some Wine-specific definitions */
 
 /* Architecture dependent settings. */