ArmVirtualizationPkg: use a HOB to store device tree blob

Instead of using a dynamic PCD, store the device tree address in a HOB
so that we can also run under a configuration that does not support
dynamic PCDs.

This also adds MemoryAllocationLib to the [LibraryClasses] section of
ArmVirtualizationPlatformLib/ArmVirtualizationPlatformLib.inf, as this
dependency was formerly satisfied transitively through one of the
library dependencies that were dropped.

Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16959 6f19259b-4bc3-4df7-8a09-765794883524

EmbeddedPkg/EmbeddedPkg.dec

@@ -52,6 +52,8 @@
   ## FDT Configuration Table
   # Include/Guid/Fdt.h
   gFdtTableGuid = { 0xb1b621d5, 0xf19c, 0x41a5, { 0x83, 0x0b, 0xd9, 0x15, 0x2c, 0x69, 0xaa, 0xe0 } }
+  # Include/Guid/FdtHob.h
+  gFdtHobGuid   = { 0x16958446, 0x19B7, 0x480B, { 0xB0, 0x47, 0x74, 0x85, 0xAD, 0x3F, 0x71, 0x6D } }
   gFdtVariableGuid = { 0x25a4fd4a, 0x9703, 0x4ba9, { 0xa1, 0x90, 0xb7, 0xc8, 0x4e, 0xfb, 0x3e, 0x57 } }
 
 [Protocols.common]