net: hns3: add debugfs support for interrupt coalesce

Since user may need to check the current configuration of the
interrupt coalesce, so add debugfs support for query this info.

Create a single file "coalesce_info" for it, and query it by
"cat coalesce_info", return the result to userspace.

For device whose version is above V3(include V3), the GL's register
contains usecs and 1us unit configuration. When get the usecs
configuration from this register, it will include the confusing unit
configuration, so add a GL mask to get the correct value, and add
a QL mask for the frames configuration as well.

The display style is below:
$ cat coalesce_info
tx interrupt coalesce info:
VEC_ID  ALGO_STATE  PROFILE_ID  CQE_MODE  TUNE_STATE  STEPS_LEFT...
0       IN_PROG     4           EQE       ON_TOP      0...
1       START       3           EQE       LEFT        1...

rx interrupt coalesce info:
VEC_ID  ALGO_STATE  PROFILE_ID  CQE_MODE  TUNE_STATE  STEPS_LEFT...
0       IN_PROG     3           EQE       LEFT        1...
1       IN_PROG     0           EQE       ON_TOP      0...

Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>