mem-cache: Added the Indirect Memory Prefetcher

mem-cache: Added the Indirect Memory Prefetcher

Reference:
    Xiangyao Yu, Christopher J. Hughes, Nadathur Satish, and Srinivas Devadas.
    2015. IMP: indirect memory prefetcher. In Proceedings of the 48th
    International Symposium on Microarchitecture (MICRO-48). ACM,
    New York, NY, USA, 178-190. DOI: https://doi.org/10.1145/2830772.2830807

Change-Id: I52790f69c13ec55b8c1c8b9396ef9a1fb1be9797
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/16223
Reviewed-by: Daniel Carvalho <odanrc@yahoo.com.br>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>