net: dsa: microchip: enable port queues for tc mqprio

LAN937x family of switches has 8 queues per port where the KSZ switches
has 4 queues per port. By default, only one queue per port is enabled.
The queues are configurable in 2, 4 or 8. This patch add 8 number of
queues for LAN937x and 4 for other switches.
In the tag_ksz.c file, prioirty of the packet is queried using the skb
buffer and the corresponding value is updated in the tag.

Signed-off-by: Arun Ramadoss <arun.ramadoss@microchip.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>