A populate() function essentially captures the value of a property,
defined by a platform, into a fconf related c structure. Such a
callback is usually platform specific and is associated to a specific
configuration source.
For example, a populate() function which captures the hardware topology
of the platform can only parse HW_CONFIG DTB. Hence each populator
function must be registered with a specific 'config_type' identifier.
It broadly represents a logical grouping of configuration properties
which is usually a device tree source file.

Example:
> TB_FW: properties related to trusted firmware such as IO policies,
	 base address of other DTBs, mbedtls heap info etc.
> HW_CONFIG: properties related to hardware configuration of the SoC
	 such as topology, GIC controller, PSCI hooks, CPU ID etc.

This patch modifies FCONF_REGISTER_POPULATOR macro and fconf_populate()
to register and invoke the appropriate callbacks selectively based on
configuration type.

Change-Id: I6f63b1fd7a8729c6c9137d5b63270af1857bb44a
Signed-off-by: Madhukar Pappireddy <madhukar.pappireddy@arm.com>

MISRA C-2012 Rule 20.7:
Macro parameter expands into an expression without being wrapped by parentheses.

MISRA C-2012 Rule 12.1:
Missing explicit parentheses on sub-expression.

MISRA C-2012 Rule 18.4:
Essential type of the left hand operand is not the same as that of the right
operand.

Include does not provide any needed symbols.

Change-Id: Ie1c6451cfbc8f519146c28b2cf15c50b1f36adc8
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>

Use the firmware configuration framework to store the io_policies
information inside the configuration device tree instead of the static
structure in the code base.

The io_policies required by BL1 can't be inside the dtb, as this one is
loaded by BL1, and only available at BL2.

This change currently only applies to FVP platform.

Change-Id: Ic9c1ac3931a4a136aa36f7f58f66d3764c1bfca1
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>