net: prestera: acl: use proper mask for port selector

Adjusted as per packet processor documentation.
This allows to properly match 'indev' for clsact rules.

Fixes: 47327e19 ("net: prestera: acl: migrate to new vTCAM api")

Signed-off-by: Maksym Glubokiy <maksym.glubokiy@plvision.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>