ArmVirtPkg, OvmfPkg: retire QemuFwCfgS3Enabled() from QemuFwCfgLib

At this point we're ready to retire QemuFwCfgS3Enabled() from the
QemuFwCfgLib class, together with its implementations in:

- ArmVirtPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c
- OvmfPkg/Library/QemuFwCfgLib/QemuFwCfgLib.c

Extend all modules that call the function with a new QemuFwCfgS3Lib class
dependency. Thanks to the previously added library class, instances, and
class resolutions, we can do this switch now as tightly as possible.

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Jordan Justen <jordan.l.justen@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=394
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>

OvmfPkg/AcpiPlatformDxe/AcpiPlatformDxe.inf

@@ -52,6 +52,7 @@
   UefiDriverEntryPoint
   HobLib
   QemuFwCfgLib
+  QemuFwCfgS3Lib
   MemoryAllocationLib
   BaseLib
   DxeServicesTableLib

OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpi.c

@@ -19,6 +19,7 @@
 #include <Library/BaseMemoryLib.h>
 #include <Library/MemoryAllocationLib.h>
 #include <Library/QemuFwCfgLib.h>
+#include <Library/QemuFwCfgS3Lib.h>
 #include <Library/DxeServicesTableLib.h>
 #include <Library/PcdLib.h>
 #include <Library/OrderedCollectionLib.h>

OvmfPkg/AcpiPlatformDxe/QemuFwCfgAcpiPlatformDxe.inf

@@ -44,6 +44,7 @@
   MemoryAllocationLib
   OrderedCollectionLib
   QemuFwCfgLib
+  QemuFwCfgS3Lib
   UefiBootServicesTableLib
   UefiDriverEntryPoint