boot/barebox/barebox.mk: fix 'allows' typo

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>
(cherry picked from commit 9e3fdb87f0e2a03e32c3a91875434f7b722a17d4)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

boot/barebox/barebox.mk

@@ -26,7 +26,7 @@ else ifeq ($$(BR2_TARGET_BAREBOX_CUSTOM_GIT),y)
 $(1)_SITE = $$(call qstrip,$$(BR2_TARGET_BAREBOX_CUSTOM_GIT_REPO_URL))
 $(1)_SITE_METHOD = git
 # Override the default value of _SOURCE to 'barebox-*' so that it is not
-# downloaded a second time for barebox-aux; also alows avoiding the hash
+# downloaded a second time for barebox-aux; also allows avoiding the hash
 # check:
 $(1)_SOURCE = barebox-$$($(1)_VERSION)$$(BR_FMT_VERSION_git).tar.gz
 else