EmbeddedPkg: delete ancient libfdt semi-integration

With all in-tree users migrated, finally delete this.
Any out-of-tree users need to migrate to MdePkg BaseFdtLib.

Signed-off-by: Leif Lindholm <[email protected]>

Author: leiflindholm

EmbeddedPkg/EmbeddedPkg.dsc

@@ -224,7 +224,6 @@
 
   EmbeddedPkg/Library/AcpiLib/AcpiLib.inf
   EmbeddedPkg/Library/DebugAgentTimerLibNull/DebugAgentTimerLibNull.inf
-  EmbeddedPkg/Library/FdtLib/FdtLib.inf
   EmbeddedPkg/Library/PrePiHobLib/PrePiHobLib.inf
   EmbeddedPkg/Library/PrePiMemoryAllocationLib/PrePiMemoryAllocationLib.inf