fconf: initial commit

Introduce the Firmware CONfiguration Framework (fconf).

The fconf is an abstraction layer for platform specific data, allowing
a "property" to be queried and a value retrieved without the requesting
entity knowing what backing store is being used to hold the data.

The default backing store used is C structure. If another backing store
has to be used, the platform integrator needs to provide a "populate()"
function to fill the corresponding C structure.
The "populate()" function must be registered to the fconf framework with
the "FCONF_REGISTER_POPULATOR()". This ensures that the function would
be called inside the "fconf_populate()" function.

A two level macro is used as getter:
- the first macro takes 3 parameters and converts it to a function
  call: FCONF_GET_PROPERTY(a,b,c) -> a__b_getter(c).
- the second level defines a__b_getter(c) to the matching C structure,
  variable, array, function, etc..

Ex: Get a Chain of trust property:
    1) FCONF_GET_PROPERY(tbbr, cot, BL2_id) -> tbbr__cot_getter(BL2_id)
    2) tbbr__cot_getter(BL2_id) -> cot_desc_ptr[BL2_id]

Change-Id: Id394001353ed295bc680c3f543af0cf8da549469
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
diff --git a/include/lib/fconf/fconf_tbbr_getter.h b/include/lib/fconf/fconf_tbbr_getter.h
new file mode 100644
index 0000000..fb81e7b
--- /dev/null
+++ b/include/lib/fconf/fconf_tbbr_getter.h
@@ -0,0 +1,15 @@
+/*
+ * Copyright (c) 2019-2020, ARM Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef FCONF_TBBR_GETTER_H
+#define FCONF_TBBR_GETTER_H
+
+#include <lib/fconf/fconf.h>
+
+/* TBBR related getter */
+#define tbbr__cot_getter(id)	cot_desc_ptr[id]
+
+#endif /* FCONF_TBBR_GETTER_H */