tools/power turbostat: Fix output formatting for ACPI CST enumeration

turbostat formatting is broken with ACPI CST for enumeration.  The
problem is that the CX_ACPI% is eight characters long which does not
work with tab formatting.  One simple solution is to remove the underbar
from the state name such that C1_ACPI will be displayed as C1ACPI.

Signed-off-by: David Arcari <darcari@redhat.com>
Cc: Len Brown <lenb@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Len Brown <len.brown@intel.com>