power: fix buffer overruns

power: fix buffer overruns

A previous change removed the limit of 64 cores by
moving away from 64-bit masks to char arrays. However
this left a buffer overrun issue, where the max channels
was defined as 64, and max cores was defined as 256. These
should all be consistently set to RTE_MAX_LCORE.

The #defines being removed are CHANNEL_CMDS_MAX_CPUS,
CHANNEL_CMDS_MAX_CHANNELS, POWER_MGR_MAX_CPUS, and
CHANNEL_CMDS_MAX_VM_CHANNELS, and are being replaced
with RTE_MAX_LCORE for consistency and simplicity.

Coverity issue: 337672, 337673, 337678
Fixes: fd73630e95c1 ("examples/power: change 64-bit masks to arrays")
Cc: stable@dpdk.org
Signed-off-by: David Hunt <david.hunt@intel.com>
Acked-by: Anatoly Burakov <anatoly.burakov@intel.com>