net/qede: fix VLAN filters

net/qede: fix VLAN filters

 - fix to prevent duplicate VLAN filters

librte_ether does not keep track of VLAN filters
configured, so it becomes driver's responsibility to
keep track of it and prevent duplicate filter
programming. The fix is to use a singly linked
list for tracking the entries and there by prevent
duplicates.

 - fix num vlan filters

Fix num vlan filter when filling Ethernet device information.

Fixes: 2ea6f76aff40 ("qede: add core driver")
Signed-off-by: Harish Patil <harish.patil@qlogic.com>