x86/resctrl: Enumerate per-thread MBA controls

x86/resctrl: Enumerate per-thread MBA controls

Some systems support per-thread Memory Bandwidth Allocation (MBA) which
applies a throttling delay value to each hardware thread instead of to
a core. Per-thread MBA is enumerated by CPUID.

No feature flag is shown in /proc/cpuinfo. User applications need to
check a resctrl throttling mode info file to know if the feature is
supported.

Signed-off-by: Fenghua Yu <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Babu Moger <[email protected]>
Reviewed-by: Reinette Chatre <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]