base: Ported circlebuf to CircularQueue

base: Ported circlebuf to CircularQueue

Ported the existing circlebuf on top of the CircularQueue to condense
shared functionality and minimise code/functionality replication.

Additional contributors: Gabor Dozsa.

Change-Id: Ib4e67c638f0fb66b54cef77007a03439218bda7f
Signed-off-by: Giacomo Gabrielli <giacomo.gabrielli@arm.com>
Signed-off-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Reviewed-on: https://gem5-review.googlesource.com/c/13128
Maintainer: Andreas Sandberg <andreas.sandberg@arm.com>
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>