This patch adds watchdog support on ARM platforms (FVP and Juno).
A secure instance of SP805 is used as Trusted Watchdog. It is
entirely managed in BL1, being enabled in the early platform setup
hook and disabled in the exit hook. By default, the watchdog is
enabled in every build (even when TBB is disabled).

A new ARM platform specific build option `ARM_DISABLE_TRUSTED_WDOG`
has been introduced to allow the user to disable the watchdog at
build time. This feature may be used for testing or debugging
purposes.

Specific error handlers for Juno and FVP are also provided in this
patch. These handlers will be called after an image load or
authentication error. On FVP, the Table of Contents (ToC) in the FIP
is erased. On Juno, the corresponding error code is stored in the
V2M Non-Volatile flags register. In both cases, the CPU spins until
a watchdog reset is generated after 256 seconds (as specified in
the TBBR document).

Change-Id: I9ca11dcb0fe15af5dbc5407ab3cf05add962f4b4

This patch migrates ARM reference platforms, Juno and FVP, to the new platform
API mandated by the new PSCI power domain topology and composite power state
frameworks. The platform specific makefiles now exports the build flag
ENABLE_PLAT_COMPAT=0 to disable the platform compatibility layer.

Change-Id: I3040ed7cce446fc66facaee9c67cb54a8cd7ca29

This patch extends the platform port by adding an API that returns
either the Root of Trust public key (ROTPK) or its hash. This is
usually stored in ROM or eFUSE memory. The ROTPK returned must be
encoded in DER format according to the following ASN.1 structure:

    SubjectPublicKeyInfo  ::=  SEQUENCE  {
        algorithm           AlgorithmIdentifier,
        subjectPublicKey    BIT STRING
    }

In case the platform returns a hash of the key:

    DigestInfo  ::= SEQUENCE {
        digestAlgorithm     AlgorithmIdentifier,
        keyDigest           OCTET STRING
    }

An implementation for ARM development platforms is provided in this
patch. When TBB is enabled, the ROTPK hash location must be specified
using the build option 'ARM_ROTPK_LOCATION'. Available options are:

    - 'regs' : return the ROTPK hash stored in the Trusted
      root-key storage registers.

    - 'devel_rsa' : return a ROTPK hash embedded in the BL1 and
      BL2 binaries. This hash has been obtained from the development
      RSA public key located in 'plat/arm/board/common/rotpk'.

On FVP, the number of MMU tables has been increased to map and
access the ROTPK registers.

A new file 'board_common.mk' has been added to improve code sharing
in the ARM develelopment platforms.

Change-Id: Ib25862e5507d1438da10773e62bd338da8f360bf

Add SP804 delay timer support to the FVP BSP.

This commit simply provides the 3 constants needed by the SP804
delay timer driver and calls sp804_timer_init() in
bl2_platform_setup(). The BSP does not currently use the delay
timer functions.

Note that the FVP SP804 is a normal world accessible peripheral
and should not be used by the secure world after transition
to the normal world.

Change-Id: I5f91d2ac9eb336fd81943b3bb388860dfb5f2b39
Co-authored-by: Dan Handley <dan.handley@arm.com>

Move the FVP port from plat/fvp to plat/arm/board/fvp. Also rename
some of the files so they are consistently prefixed with fvp_.
Update the platform makefiles accordingly.

Change-Id: I7569affc3127d66405f1548fc81b878a858e61b7