bootctl: add --print-efi-architecture switch

This is extremely useful for our own test cases, since acquiring the
right EFI architecture string is otherwise a bit nasty.

shell-completion/bash/bootctl

@@ -35,6 +35,7 @@ _bootctl() {
         [STANDALONE]='-h --help --version
                       -p --print-esp-path -x --print-boot-path --print-loader-path
                       --print-stub-path -R --print-root-device -RR
+                      --print-efi-architecture
                       --no-pager --graceful -q --quiet --all-architectures
                       --dry-run'
         [ARG]='--esp-path --boot-path --root --image --image-policy --install-source

shell-completion/zsh/_bootctl

@@ -74,6 +74,7 @@ _arguments \
     '--boot-path=[Path to the $BOOT partition]:path:_directories' \
     '(-p --print-esp-path)'{-p,--print-esp-path}'[Print path to the EFI system partition]' \
     '(-x --print-boot-path)'{-x,--print-boot-path}'[Print path to the $BOOT partition]' \
+    '--print-efi-architecture[Print the EFI architecture identifier]' \
     '--make-machine-id-directory=[Control creation and deletion of the top-level machine ID directory.]:options:(yes no auto)' \
     '--no-pager[Do not pipe output into a pager]' \
     '--graceful[Do not fail when locating ESP or writing fails]' \