tools/power turbostat: fix buffer overrun

turbostat could be terminated by general protection fault on some latest
hardwares which (for example) support 9 levels of C-states and show 18
"tADDED" lines. That bloats the total output and finally causes buffer
overrun.  So let's extend the buffer to avoid this.

Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Signed-off-by: Len Brown <len.brown@intel.com>