ArmPlatformPkg/Bds: Restore the setting of the FDT device path in the boot manager

ArmPlatformPkg/Bds: Restore the setting of the FDT device path in the boot manager

People has requested this feature to be restaured in the
ARM Boot Manager.
The configuration from the EFI Shell is always possible
and it is the recommended approach to update the FDT
Device Path.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Ronald Cron <Ronald.Cron@arm.com>
Reviewed-by: Olivier Martin <Olivier.Martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17826 6f19259b-4bc3-4df7-8a09-765794883524