mem-cache: Generate error on compression misconfiguration

mem-cache: Generate error on compression misconfiguration

Compressed caches must use the compressed tags, otherwise a
seg fault will be generated. Besides, if no compressor is
assigned; yet compressed tags are used, data is not compressed.

Generate an error for the first case, and a warning for the
second.

Change-Id: Iac5474ed919163ce38a8c4e8efd9727e5b3d8417
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/38635
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>