net: hns3: move dump regs function to a separate file

The dump register function is being refactored.
The first step in refactoring is put the dump regs function
into a separate file.

Signed-off-by: Jijie Shao <shaojijie@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>