OvmfPkg: Create global entry point for SMBIOS parsing

Move the generic entry point part out of Qemu.c to anticipate the
addition of new ways of retrieving the SMBIOS table.

Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Signed-off-by: Sebastien Boeuf <sebastien.boeuf@intel.com>

OvmfPkg/SmbiosPlatformDxe/SmbiosPlatformDxe.h

@@ -22,4 +22,15 @@ InstallAllStructures (
   IN UINT8  *TableAddress
   );
 
+/**
+  Locates and extracts the QEMU SMBIOS data if present in fw_cfg
+
+  @return                 Address of extracted QEMU SMBIOS data
+
+**/
+UINT8 *
+GetQemuSmbiosTables (
+  VOID
+  );
+
 #endif