tools/power/x86/intel-speed-select: Enhance help

Enhance help message which adds some example. The changes include:
- Print help when options are not recognized.
- For CLX, display only options which are applicable.
- Sort options in alphatical order.
- Disply help() instead of error:
"Feature name and|or command not specified"
- Remove duplicate display of
Intel(R) Speed Select Technology

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