libsodium: don’t link tests when TEST_ALL=1 is used

Currently libsodium tests add about 800kB to the binary, which is too
much for a partition table constrained to 2MB. Disable libsodium tests
until we start building multiple unit test apps for different subsets.

components/libsodium/test/component.mk

@@ -4,7 +4,11 @@
 
 LS_TESTDIR := ../libsodium/test/default
 
+ifdef TESTS_ALL
+$(info not linking libsodium tests, use 'TEST_COMPONENTS=libsodium' to test it)
+else
 COMPONENT_ADD_LDFLAGS = -Wl,--whole-archive -l$(COMPONENT_NAME) -Wl,--no-whole-archive
+endif # TESTS_ALL
 
 COMPONENT_SRCDIRS := . $(LS_TESTDIR)