contrib: force top Makefile to not be parallelizable

Set .NOTPARALLEL target to enforce non-parallelizable
top Makefile rules. This protect agains two parallel builds
of inter-dependant libraries.
But each package continue to use the multi-job option if given.

Reviewed-by: Alexandre Viau <alexandre.viau@savoirfairelinux.com>
Change-Id: I98ae532dcc924ef5cae1ea235a807469ed77ed99

contrib/src/main.mak

@@ -505,3 +505,8 @@ $(patsubst %,.dep-%,$(filter-out $(PKGS_FOUND),$(PKGS_ALL))): .dep-%: .%
 $(foreach p,$(PKGS_ALL),.$(p)): .%: $$(foreach d,$$(DEPS_$$*),.dep-$$(d))
 
 .DELETE_ON_ERROR:
+
+# Disable -j option for the top Makefile as this framework doesn't support well
+# this and some contrib may be not well build or even not build at all.
+# Notice that projects' rules.mak file use parallel jobs even with this.
+.NOTPARALLEL:
\ No newline at end of file