[][kernel][common][eth][Add debug information to the SFP]

Add debug information to the SFP.

In this patch, we provide the following information to assist
users in easily locating issues.
  - Dump SFP state machine
  - Dump System/Line interface status
  - Dump SFP, PHY, and Host link mode
If debug messages is too annoying, user can disable it by "dmesg -n 7"

Without this patch, users cannot locate SFP issues easily.


Change-Id: I567ed96bfb489cecb1887cd08518d01a7ed33657
Reviewed-on: https://gerrit.mediatek.inc/c/openwrt/feeds/mtk_openwrt_feeds/+/7714996
1 file changed