intel-pstate: Add more debug to driver probe
Make it easier to see which features are used on the system by summarising the features the driver will use.
** (power-profiles-daemon:126721): DEBUG: Found Intel p-state settings
** (power-profiles-daemon:126721): DEBUG: Energy Performance Preference: yes
** (power-profiles-daemon:126721): DEBUG: Energy Performance Bias: yes
** (power-profiles-daemon:126721): DEBUG: Has Turbo: yes
Closes: #120 (closed)