eal/linux: add interrupt type for vdev

eal/linux: add interrupt type for vdev

A new interrupt type, RTE_INTR_HANDLE_VDEV, is added to support lsc and rxq
interrupt for vdev.

For lsc interrupt, except from original EPOLLIN events, we also listen for
socket peer closed connection event (EPOLLRDHUP and EPOLLHUP).

For rxq interrupt, add a precondition to avoid invoking any vfio and uio
code.

For intr_handle initialization, let each vdev driver to do that.

Signed-off-by: Jianfeng Tan <jianfeng.tan@intel.com>