net: dsa: qca8k: cache match data to speed up access

Using of_device_get_match_data is expensive. Cache match data to speed
up access and rework user of match data to use the new cached value.

Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>