Update git submodules

* Update docs/submodules/fuel from branch 'stable/fraser'
  - Merge "maas: boot-resources: Dynamic arch list from PDF" into stable/fraser
  - maas: boot-resources: Dynamic arch list from PDF

    Instead of leaving MaaS default to 'amd64', explicitly set the list
    of architectures to support based on PDF data.

    Change-Id: I852a3ce156db3df0c090f10c0b45c26058dbb6c6
    Signed-off-by: Alexandru Avadanii <Alexandru.Avadanii@enea.com>
    (cherry picked from commit be45e3157fe19b8905e3a30f7f839a728a6c6df7)

diff --git a/docs/submodules/fuel b/docs/submodules/fuel
index 996a8a8..58615ef 160000 (submodule)
--- a/docs/submodules/fuel
+++ b/docs/submodules/fuel
@@ -1 +1 @@
-Subproject commit 996a8a8518d5e3baf72b7882112f4a15c184b5eb
+Subproject commit 58615ef93be91652da9dcef3ac797d11c5cc7e88