tc0: Remove platform code

TC0 platform was deprecated about a year ago.
Now remove the platform code as per the project's rules.

858076b2: (tc0: Deprecate platform)

Signed-off-by: Nicola Mazzucato <nicola.mazzucato@arm.com>
Change-Id: I41b63ead658ee2592c3e422a3cd514c120156e01