examples/l3fwd-power: add high/regular perf cores options

examples/l3fwd-power: add high/regular perf cores options

Added high/regular performance core pinning configuration options
that can be used in place of the existing 'config' option.

'--high-perf-cores CORELIST' option allow the user to specify a
high performance cores list; if this option is not used and the
'perf-config' option is used, the application will query the
system using the rte_power library in order to get a list of
available high performance cores. The cores that are considered
high performance are the cores that have turbo enabled.

'--perf-config (port,queue,hi_perf,lcore_index)'
option is similar to the existing config option, the cores are specified
as indices for bins containing high or regular performance cores.

Example:

l3fwd-power -l 6,7 -- -p 0xff \
--high-perf-cores 6 --perf-config="(0,0,0,0),(1,0,1,0)"

cores 6 and 7 are used, core 6 is specified as a high performance core.
port 0 queue 0 will use a regular performance core, index 0 (core 7)
port 1 queue 0 will use a high performance core, index 0 (core 6)

Signed-off-by: Radu Nicolau <radu.nicolau@intel.com>
Acked-by: David Hunt <david.hunt@intel.com>