tools/power/turbostat: Use fine grained IRTL output

It is pointless to dump the IRTL register for a package cstate that is
not supported by the platform.

Print IRTL only for states that are available in
platform->supported_cstates.

Delete has_c8910_msrs() CPU model check.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Reviewed-by: Len Brown <len.brown@intel.com>