kconfig: tests: Fix double 'source' of subsys/testsuite/Kconfig

Both Kconfig.zephyr and subsys/Kconfig 'source's
subsys/testsuite/Kconfig, giving multiple redundant identical
definitions for all the symbols in it.

Remove the 'source' in Kconfig.zephyr.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
1 file changed