Add compile option to disable floating point usage (#114)

This commit adds the option to disable floating point processing in
QCBOR. To disable, the USEFULBUF_DISABLE_ALL_FLOAT preprocessor macro
needs to be defined.

e.g.:

 $ make CMD_LINE="-DUSEFULBUF_DISABLE_ALL_FLOAT"

This removes the capability (and the code) of decoding floating point
types. The type is still recognised, so a meaningful
QCBOR_ERR_ALL_FLOAT_DISABLED error is returned when a floating point value
is encountered in a decoded qcbor. From the encoding interface the
floating point encoding functions are removed.

Change-Id: I371769246f7d83354607de9bce1e7998b8c536a1
Signed-off-by: Mate Toth-Pal <mate.toth-pal@arm.com>
diff --git a/test/UsefulBuf_Tests.h b/test/UsefulBuf_Tests.h
index 976de62..0d06206 100644
--- a/test/UsefulBuf_Tests.h
+++ b/test/UsefulBuf_Tests.h
@@ -1,6 +1,7 @@
 /*==============================================================================
  Copyright (c) 2016-2018, The Linux Foundation.
  Copyright (c) 2018, Laurence Lundblade.
+ Copyright (c) 2021, Arm Limited.
  All rights reserved.
 
 Redistribution and use in source and binary forms, with or without
@@ -45,6 +46,8 @@
 
 const char *  UIBTest_IntegerFormat(void);
 
+#ifndef USEFULBUF_DISABLE_ALL_FLOAT
 const char *  UBUTest_CopyUtil(void);
+#endif /* USEFULBUF_DISABLE_ALL_FLOAT */
 
 #endif