Encapsulate all branch-prediction-related files in a branch_prediction namespace. This will allow these files to be renamed to drop the BP suffix. Issued-on: https://gem5.atlassian.net/browse/GEM5-982 Change-Id: I640c0caa846a3aade6fae95e9a93e4318ae9fca0 Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br> Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/47303 Reviewed-by: Bobby R. Bruce <bbruce@ucdavis.edu> Maintainer: Bobby R. Bruce <bbruce@ucdavis.edu> Tested-by: kokoro <noreply+kokoro@google.com>