examples/ip_pipeline: fix coremask limitation

examples/ip_pipeline: fix coremask limitation

Issue:
coremask used in IP Pipeline is limited to 64 cores.

Solution:
Modified coremask as an array of uint64_t to support RTE_MAX_LCORE

Fixes: 7f64b9c004aa ("examples/ip_pipeline: rework config file syntax")
Fixes: eb32fe7c5574 ("examples/ip_pipeline: rework initialization parameters")
Fixes: b4aee0fb9c6d ("examples/ip_pipeline: reconfigure thread binding dynamically")
Fixes: 4e14069328fc ("examples/ip_pipeline: measure CPU utilization")
Signed-off-by: Sankar Chokkalingam <sankarx.chokkalingam@intel.com>
Acked-by: Cristian Dumitrescu <cristian.dumitrescu@intel.com>