mem: Remove unused 'using namespace'

Removal of unused/barely used 'using namespace' from C++ files.

Change-Id: I66dc548c04506db2e41180b9ea7ab5abd7d5375a
Reviewed-on: https://gem5-review.googlesource.com/9601
Reviewed-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

style: [patch 1/22] use /r/3648/ to reorganize includes

mem: Fix search-replace issues in DRAMPower wrapper license

Fix a number of unintentional insertions of 'const'.

mem: Add a GDDR5 DRAM config

This patch adds a first cut GDDR5 config to accommodate the users
combining gem5 and GPUSim. The config is based on a SK Hynix
datasheet, and the Nvidia GTX580 specification. Someone from the
GPUSim user-camp should tweak the default page-policy and static
frontend and backend latencies.

mem: Add DRAMPower wrapping class

This patch adds a class to wrap DRAMPower Library in gem5.
This class initiates an object of class MemorySpecification
of the DRAMPower Library, passes the parameters from DRAMCtrl.py
to this object and creates an object of drampower library using
the memory specification.