Update git submodules

* Update docs/submodules/fuel from branch 'stable/fraser'
  - Merge "AArch64: Switch back to hwe-16.04 kernel" into stable/fraser
  - AArch64: Switch back to hwe-16.04 kernel

    Align kernel versions across architectures (where possible).

    Change-Id: I66a822611eb5e46f90b62f5d36df571ae75dcba3
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit 931141e84500695b4a278cc04888b603749a8303)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index e668512..f63c58f 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit e6685124258ed9d1237acf9d8b383c07f1397f93
+Subproject commit f63c58f98b6ddbf64f300ed0495be3dd88e242e0