BL3-1 architecture setup code programs the system counter frequency
into the CNTFRQ_EL0 register. This frequency is defined by the
platform, though. This patch introduces a new platform hook that
the architecture setup code can call to retrieve this information.
In the ARM FVP port, this returns the first entry of the frequency
modes table from the memory mapped generic timer.

All system counter setup code has been removed from BL1 as some
platforms may not have initialized the system counters at this stage.
The platform specific settings done exclusively in BL1 have been moved
to BL3-1. In the ARM FVP port, this consists in enabling and
initializing the System level generic timer. Also, the frequency change
request in the counter control register has been set to 0 to make it
explicit it's using the base frequency. The CNTCR_FCREQ() macro has been
fixed in this context to give an entry number rather than a bitmask.

In future, when support for firmware update is implemented, there
is a case where BL1 platform specific code will need to program
the counter frequency. This should be implemented at that time.

This patch also updates the relevant documentation.

Change-Id: I559c5a4d86cad55ce3f6ad71285b538d3cfd76dc
Signed-off-by: Jon Medhurst <tixy@linaro.org>

This patch factors out the ARM FVP specific code to create MMU
translation tables so that it is possible for a boot loader stage to
create a different set of tables instead of using the default ones.
The default translation tables are created with the assumption that
the calling boot loader stage executes out of secure SRAM. This might
not be true for the BL3_2 stage in the future.

A boot loader stage can define the `fill_xlation_tables()` function as
per its requirements. It returns a reference to the level 1
translation table which is used by the common platform code to setup
the TTBR_EL3.

This patch is a temporary solution before a larger rework of
translation table creation logic is introduced.

Change-Id: I09a075d5da16822ee32a411a9dbe284718fb4ff6

This patch moves the translation tables into their own section. This
saves space that would otherwise have been lost in padding due to page
table alignment constraints. The BL31 and BL32 bases have been
consequently adjusted.

Change-Id: Ibd65ae8a5ce4c4ea9a71a794c95bbff40dc63e65

Also fix warnings generated in release builds when assert code
is absent.

Change-Id: I45b9173d3888f9e93e98eb5b4fdc06727ba5cbf4

The FVP platform has a few filenames that begin with fvp_.  These are
renamed to plat_ to make it easier to use the FVP port as a template.

Change-Id: I601e6256d5ef3bae81a2e1f5df6de56db5b27069
Signed-off-by: Ryan Harkin <ryan.harkin@linaro.org>