e2k: add a stub for non e2k%

use/e2k/multiseat/full invoked from many targets, regardless of the
fact that it is e2k.

features.in/e2k/config.mk

@@ -1,3 +1,4 @@
+ifeq (,$(filter-out e2k%,$(ARCH)))
 use/e2k: use/tty/S0 use/l10n/default/ru_RU
 	@$(call add_feature)
 	@$(call add,BASE_PACKAGES,installer-feature-e2k-fix-clock-stage3)
@@ -68,3 +69,7 @@ use/e2k/sound/401:
 else
 use/e2k/sound/401:; @:
 endif	# e2k
+else
+use/e2k:; @:
+use/e2k/%:; @:
+endif	# e2k%