mem-cache: Store BDI's encoding in tags

According to the original paper the compressors' encodings are
stored in the tag-store (Storage cost analysis section).

Change-Id: I4c34f86022eea6d1ba0ae29dd74d5714bbad367a
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/33381
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
diff --git a/src/mem/cache/compressors/Compressors.py b/src/mem/cache/compressors/Compressors.py
index f7e8a7d..45effe9 100644
--- a/src/mem/cache/compressors/Compressors.py
+++ b/src/mem/cache/compressors/Compressors.py
@@ -145,6 +145,7 @@
     chunk_size_bits = 64
 
 class BDI(MultiCompressor):
+    encoding_in_tags=True
     compressors = [ZeroCompressor(), RepeatedQwordsCompressor(),
         Base64Delta8(), Base64Delta16(), Base64Delta32(), Base32Delta8(),
         Base32Delta16(), Base16Delta8()]