tools: L2 CAT: support get HW info for L2 CAT.

tools: L2 CAT: support get HW info for L2 CAT.

This patch implements xl/xc changes to support get HW info
for L2 CAT.

'xl psr-hwinfo' is updated to show both L3 CAT and L2 CAT
info.

Example(on machine which only supports L2 CAT):
Cache Monitoring Technology (CMT):
Enabled         : 0
Cache Allocation Technology (CAT): L2
Socket ID       : 0
Maximum COS     : 3
CBM length      : 8
Default CBM     : 0xff

Signed-off-by: He Chen <he.chen@linux.intel.com>
Signed-off-by: Yi Sun <yi.y.sun@linux.intel.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>