net: ena: cosmetic: set queue sizes to u32 for consistency

Make all types of variables that convey the number and sizeof queues to
be u32, for consistency with the API between the driver and device via
ena_admin_defs.h:ena_admin_get_feat_resp.max_queue_ext fields. Current
code sometimes uses int and there are multiple assignments between these
variables with different types.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>