tools/power/x86/intel-speed-select: Check feature status first

Before looking for information about the base-freq or turbo-freq details,
first check if the feature is supported at that level. If not print error
and return.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>