event/dlb2: remove duplicate/unused PCI code
event/dlb2: remove duplicate/unused PCI code

Use rte_pci_find_ext_capability instead of private version,
Remove unused PCI offsets and values
Use PCI definitions from rte_pci.h, where available.

Signed-off-by: Timothy McDaniel <190d0658596d144b7d6e7de3c5d6e0f14d01ed54@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk