Makefile.include: Add line continuations between $(eval) calls

Older GNU Make versions (e.g. v4.1) don't like the `mark_missing_deps`
macro without line continuations. Probably because the lines are tech-
nically empty after evaluation.

Change-Id: I790c21999b2fc9c698f6bf9302f670470fe1bab8
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: https://review.coreboot.org/c/flashrom-stable/+/73749
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/Makefile.include b/Makefile.include
index aa4a3d1..1bca4f3 100644
--- a/Makefile.include
+++ b/Makefile.include
@@ -24,8 +24,8 @@
 $(foreach p,$2, \
 	$(if $(filter $($(p)),yes), \
 		$(eval MISSING_DEPENDENCY += $(1)) \
-		$(eval MISSING_DEPENDENCY_$(1) += $(p)=yes)))
-$(eval MISSING_DEPENDENCY := $(sort $(MISSING_DEPENDENCY)))
+		$(eval MISSING_DEPENDENCY_$(1) += $(p)=yes))) \
+$(eval MISSING_DEPENDENCY := $(sort $(MISSING_DEPENDENCY))) \
 $(eval MISSING_DEPENDENCY_NOTE_$(1) := $(if $(3),$(3),""))
 endef