Marvell: Introduce MARVELL_BOARD_DESC_PROTOCOL

This patch introduces protocol that exposes generic API to get board
description. It uses ArmadaSoCDescLib library, which is implemented per
SoC family to get the SoC level description for hardware module controller.
Together with the information obtained from ArmadaBoardDescLib
the protocol allows the drivers to get per-board information about
used hardware and settings.
As a first usage a UTMI information obtaining is implemented.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>