net/i40e: fix global register recovery

net/i40e: fix global register recovery

PMD configures the global register I40E_GLINT_CTL during
device initialization to work around the Rx write back
issue. But when a device is bound from DPDK to kernel,
the global register is not recovered to the original
state, it will cause kernel driver performance drop issue.
This patch fixes this issue.

Fixes: be6c228d4da3 ("i40e: support Rx interrupt")
Fixes: 4ab831449a1c ("net/i40e: fix interrupt conflict with multi-driver")
Cc: stable@dpdk.org
Signed-off-by: Beilei Xing <beilei.xing@intel.com>
Acked-by: Jeff Guo <jia.guo@intel.com>