bump version to 5.6 and disable a warning am: 5325bb91d5 am: 84b12bf8c6 am: ba58d83a03

Original change: https://android-review.googlesource.com/c/platform/external/ethtool/+/2804534

Change-Id: Iac71f46619233a312e0c207ee5e64fd16bcdb756
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>