Move MulDiv prototype from wingdi.h to winbase.h where it belongs.

diff --git a/include/winbase.h b/include/winbase.h
index f5630d4..be87a65 100644
--- a/include/winbase.h
+++ b/include/winbase.h
@@ -1520,6 +1520,7 @@
 BOOL        WINAPI MoveFileExA(LPCSTR,LPCSTR,DWORD);
 BOOL        WINAPI MoveFileExW(LPCWSTR,LPCWSTR,DWORD);
 #define     MoveFileEx WINELIB_NAME_AW(MoveFileEx)
+INT         WINAPI MulDiv(INT,INT,INT);
 BOOL        WINAPI NotifyChangeEventLog(HANDLE,HANDLE);
 HANDLE      WINAPI OpenBackupEventLogA(LPCSTR,LPCSTR);
 HANDLE      WINAPI OpenBackupEventLogW(LPCWSTR,LPCWSTR);
diff --git a/include/wingdi.h b/include/wingdi.h
index ba84e5e..a84241d 100644
--- a/include/wingdi.h
+++ b/include/wingdi.h
@@ -3458,8 +3458,6 @@
 BOOL        WINAPI MaskBlt(HDC,INT,INT,INT,INT,HDC,INT,INT,HBITMAP,INT,INT,DWORD);
 BOOL        WINAPI ModifyWorldTransform(HDC,const XFORM *, DWORD);
 BOOL        WINAPI MoveToEx(HDC,INT,INT,LPPOINT);
-/* FIXME This is defined in kernel32.spec !?*/
-INT       WINAPI MulDiv(INT,INT,INT);
 INT       WINAPI OffsetClipRgn(HDC,INT,INT);
 INT       WINAPI OffsetRgn(HRGN,INT,INT);
 BOOL      WINAPI OffsetViewportOrgEx(HDC,INT,INT,LPPOINT);