x86/resctrl: Create mba_sc configuration in the rdt_domain

To support resctrl's MBA software controller, the architecture must provide
a second configuration array to hold the mbps_val[] from user-space.

This complicates the interface between the architecture specific code and
the filesystem portions of resctrl that will move to /fs/, to allow
multiple architectures to support resctrl.

Make the filesystem parts of resctrl create an array for the mba_sc
values. The software controller can be changed to use this, allowing
the architecture code to only consider the values configured in hardware.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Jamie Iles <quic_jiles@quicinc.com>
Reviewed-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Xin Hao <xhao@linux.alibaba.com>
Tested-by: Shaopeng Tan <tan.shaopeng@fujitsu.com>
Tested-by: Cristian Marussi <cristian.marussi@arm.com>
Link: https://lore.kernel.org/r/20220902154829.30399-9-james.morse@arm.com