wil6210: enable access category queues

Set ac_queues default to enabled.
Change wil_select_ac_queue to return higher priority queue for EAPOL,
ARP and ICMP packets. These special packets are critical to maintain
the link with the AP and guarantee healthy operations and diagnostics
in the network.

Special packets will get the higher priority to ensure early
transmission when access category is enabled.

Change-Id: Ic03a810c303f614174f9f10c72e339ee32a6f023
Signed-off-by: Ahmad Masri <amasri@codeaurora.org>