Platform: Remove Musca_A platform code (Deprecation)

This patch removes Musca A board from platform
code-base and documentation.

Signed-off-by: Minos Galanakis <minos.galanakis@arm.com>
Change-Id: I613eac2b478655b6b6f8195339b2502f1c5a79b9
70 files changed