This patch adds support for Measured Boot driver functionality
in common Arm platform code.

Change-Id: If049dcf8d847c39023b77c0d805a8cf5b8bcaa3e
Signed-off-by: Alexei Fedorov <Alexei.Fedorov@arm.com>

The chain of trust array is now always accessed through a fconf getter.
This gives us an ideal spot to check for out-of-bound accesses.

Change-Id: Ic5ea20e43cf8ca959bb7f9b60de7c0839b390add
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>

Use the firmware configuration framework in arm dynamic configuration
to retrieve mbedtls heap information between bl1 and bl2.

For this, a new fconf getter is added to expose the device tree base
address and size.

Change-Id: Ifa5ac9366ae100e2cdd1f4c8e85fc591b170f4b6
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

Use fconf to retrieve the `disable_authentication` property.
Move this access from arm dynamic configuration to bl common.

Change-Id: Ibf184a5c6245d04839222f5457cf5e651f252b86
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

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>