rpi3: Use new console APIs

Switch to the new console APIs enabled by setting MULTI_CONSOLE_API=1.

The crash console doesn't use this API, it uses internally the core
functions of the 16550 console.

`bl31_plat_runtime_setup` is no longer needed. When this platform port
was introduced, that function used to disable the console. It was needed
to override that behaviour. The new behaviour is to switch to the
runtime console. The console is registered for all scopes (boot, crash
and runtime) in `rpi3_console_init` so it is not needed to override the
default behaviour anymore.

Update documentation.

Change-Id: If2ee8f91044216183b7ef142e5c05ad6220ae92f
Signed-off-by: Antonio Nino Diaz <antonio.ninodiaz@arm.com>
diff --git a/docs/plat/rpi3.rst b/docs/plat/rpi3.rst
index c30110e..b7879a8 100644
--- a/docs/plat/rpi3.rst
+++ b/docs/plat/rpi3.rst
@@ -247,6 +247,11 @@
 
 - ``LOAD_IMAGE_V2=0``: Only version 2 is supported.
 
+- ``MULTI_CONSOLE_API=0``: The multi console API must be enabled. Note that the
+  crash console uses the internal 16550 driver functions directly in order to be
+  able to print error messages during early crashes before setting up the
+  multi console API.
+
 AArch64 kernel build instructions
 ---------------------------------
 
@@ -300,7 +305,7 @@
 
 The instructions assume that you have an SD card with a fresh install of
 `Raspbian`_ (or that, at least, the ``boot`` partition is untouched, or nearly
-untouched). They have been tested with the image available in 2017-09-07.
+untouched). They have been tested with the image available in 2018-03-13.
 
 1. Insert the SD card and open the ``boot`` partition.