Standardise header guards across codebase ...

All identifiers, regardless of use, that start with two underscores are
reserved. This means they can't be used in header guards.

The style that this project is now to use the full name of the file in
capital letters followed by 'H'. For example, for a file called
"uart_example.h", the header guard is UART_EXAMPLE_H.

The exceptions are files that are imported from other projects:

- CryptoCell driver
- dt-bindings folders
- zlib headers

Change-Id: I50561bf6c88b491ec440d0c8385c74650f3c106e
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>

plat/arm: Fix misra warnings in platform code ...

Change-Id: Ica944acc474a099219d50b041cfaeabd4f3d362f
Signed-off-by: Sathees Balya <sathees.balya@arm.com>

GIC: Allow specifying interrupt properties ...

The GIC driver initialization currently allows an array of interrupts to
be configured as secure. Future use cases would require more interrupt
configuration other than just security, such as priority.

This patch introduces a new interrupt property array as part of both
GICv2 and GICv3 driver data. The platform can populate the array with
interrupt numbers and respective properties. The corresponding driver
initialization iterates through the array, and applies interrupt
configuration as required.

This capability, and the current way of supplying array (or arrays, in
case of GICv3) of secure interrupts, are however mutually exclusive.
Henceforth, the platform should supply either:

  - A list of interrupts to be mapped as secure (the current way).
    Platforms that do this will continue working as they were. With this
    patch, this scheme is deprecated.

  - A list of interrupt properties (properties include interrupt group).
    Individual interrupt properties are specified via. descriptors of
    type 'interrupt_prop_desc_t', which can be populated with the macro
    INTR_PROP_DESC().

A run time assert checks that the platform doesn't specify both.

Henceforth the old scheme of providing list of secure interrupts is
deprecated. When built with ERROR_DEPRECATED=1, GIC drivers will require
that the interrupt properties are supplied instead of an array of secure
interrupts.

Add a section to firmware design about configuring secure interrupts.

Fixes ARM-software/tf-issues#262

Change-Id: I8eec29e72eb69dbb6bce77879febf32c95376942
Signed-off-by: Jeenu Viswambharan <jeenu.viswambharan@arm.com>