iwlwifi: fw: uefi: add missing include guards

iwlwifi: fw: uefi: add missing include guards

We still don't use #pragma once in the kernel, but even if
we did it'd be missing. Add the missing include guards.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Fixes: 84c3c9952afb ("iwlwifi: move UEFI code to a separate file")
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211024181719.7fc9988ed49b.I87e300fab664047581e51fb9b02744c75320d08c@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>