Marvell/Drivers: XenonDxe: Switch to use generic SdMmcPciHcDxe

XenonDxe was copy of SdMmcPciHcDxe from edk2/MdeModulePkg.

Now it implements SdMmcOverride protocol which allows
to add quirks to the generic SdMmcPciHcDxe.

Platforms that were using XenonDxe/SdMmcPciHcDxe have fixed *.fdf
and *.dsc.inc files to use new implementation of XenonDxe.

In the new version of the driver apart from using SdMmcOverride
protocol, this patch utilizes newly added controllers'
description in MvBoardDesc protocol, as well as improved
PHY configuration sequence.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>