net: hns3: refactor interrupt coalescing init function

In the hardware, the coalesce configurable registers include GL0, GL1,
GL2. In the driver, the TX queues use the register GL1 and the RX queues
use the register GL0. This function initializes the configuration of the
interrupt coalescing, but does not distinguish between the TX direction
and the RX direction. It will cause some confusion.

This patch refactors the function to initialize the TX GL and the RX GL
separately. And the initialization of related variables also is added to
this patch.

Signed-off-by: Fuyun Liang <liangfuyun1@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>