EmbeddedPkg : Add FdtPlatformDxe driver

EmbeddedPkg : Add FdtPlatformDxe driver

The FdtPlatformDxe driver installs the FDT of the platform it
is running on into the UEFI Configuration table at the end of
the DXE phase.

Please refer to the README.txt file for a global overview of
the driver.

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@16933 6f19259b-4bc3-4df7-8a09-765794883524