Juno: Implement initial platform port

This patch adds the initial port of the ARM Trusted Firmware on the Juno
development platform. This port does not support a BL3-2 image or any PSCI APIs
apart from PSCI_VERSION and PSCI_CPU_ON. It enables workarounds for selected
Cortex-A57 (#806969 & #813420) errata and implements the workaround for a Juno
platform errata (Defect id 831273).

Change-Id: Ib3d92df3af53820cfbb2977582ed0d7abf6ef893
Juno: Implement PSCI CPU_OFF and CPU_SUSPEND APIs

This patch adds support for PSCI CPU_OFF and CPU_SUSPEND APIs to the Juno port
of the ARM Trusted Firmware. The maximum affinity level that can be suspended is
the cluster level (affinity level 1). Support for suspending the system level is
not present.

Change-Id: Ie2c9da0acd7d1b0d5ac64940cdf40347153e52c8
Juno: Add support for Test Secure-EL1 Payload

This patch implements the TSP on Juno. It executes from on-chip Trusted
SRAM.

Also, the other bootloader images (i.e. BL1 R/W, BL2 and BL3-1) have
been moved around. The reason is, although there was enough space
overall to store the TSP in SRAM, there was no contiguous free chunk
of SRAM big enough to hold it.

This patch keeps the overall memory layout (i.e. keeping BL1 R/W at
the bottom, BL2 at the top and BL3-1 in between) but moves the base
addresses of all the bootloader images in such a way that:
 - memory fragmentation is reduced enough to fit BL3-2 in;
 - new base addresses are suitable for release builds as well as debug
   ones;
 - each image has a few extra kilobytes for future growth.
   BL3-1 and BL3-2 are the images which received the biggest allocations
   since they will most probably grow the most.

This patch also adds instruction synchronization barriers around the code which
handles the timer interrupt in the TSP. This ensures that the interrupt is not
acknowledged after or EOIed before it is deactivated at the peripheral.

Change-Id: I1c5b51858700027ee283ac85d18e06863a27c72e
Juno: Implement PSCI SYSTEM_OFF and SYSTEM_RESET APIs

This patch adds the Juno platform specific handlers for PSCI
SYSTEM_OFF and SYSTEM_RESET operations.

Change-Id: Ie389adead533ec2314af44d721b4d0f306147c7d
Juno: Read primary CPU MPID from SCC GPR_1

This patch removes the PRIMARY_CPU definition hardcoded in the
Juno port. Instead, the primary CPU is obtained at runtime by
reading the SCC General Purpose Register 1 (GPR_1), whose value
is copied by the SCP into shared memory during the boot process.

Change-Id: I3981daa92eb7142250712274cf7f655b219837f5
Merge pull request #196 from soby-mathew/sm/tf_juno_support

Add support for Juno in Trusted Firmware