detect: Adding more CPU information

Let's report for each socket, it's product name, vendor, frequency &
clock

A typical output is :

 ('cpu', 'physical_0', 'physid', '1'),
 ('cpu', 'physical_0', 'product', 'Intel(R) Core(TM) i5-3320M CPU @ 2.60GHz'),
 ('cpu', 'physical_0', 'vendor', 'Intel Corp.'),
 ('cpu', 'physical_0', 'frequency', '1200000000'),
 ('cpu', 'physical_0', 'clock', '100000000'),
 ('cpu', 'physical_0', 'cores', '2'),
 ('cpu', 'physical_0', 'enabled_cores', '2'),
 ('cpu', 'physical_0', 'threads', '4'),
 ('cpu', 'physical', 'number', 1),