Add back Platform.h clangd throught it did not need the macro for sscanf

Signed-off-by: Kevin Wheatley <kevin.wheatley@framestore.com>

Author: KevinJW

src/OpenColorIO/fileformats/FileFormatDiscreet1DL.cpp

@@ -18,6 +18,7 @@
 #include "BitDepthUtils.h"
 #include "fileformats/FileFormatUtils.h"
 #include "ops/lut1d/Lut1DOp.h"
+#include "Platform.h"
 #include "transforms/FileTransform.h"
 #include "utils/StringUtils.h"