tests: move kernel tests to tests/legacy

Move all kernel tests using legacy APIs into tests/legacy to continue testing
old APIs and compatibility. We keep in tests/kernel those tests that do not use
any kernel APIs and generic in nature, those should not be affected by the
unified kernel API change.

In tests/kernel we will start adding tests that are unified kernel only. Later
and when deprecation period is over the legacy tests would be dropped.

Change-Id: Icc7d8c7e5f2af65af350b75da3117f72396925f4
Signed-off-by: Anas Nashif <anas.nashif@intel.com>

tests/kernel/test_timer/microkernel/src/Makefile

@@ -1,4 +0,0 @@
-ccflags-y += -I${ZEPHYR_BASE}/tests/include \
-    -I$(ZEPHYR_BASE)/tests/kernel/test_fifo/nanokernel/src/
-
-obj-y = timer.o

tests/legacy/kernel/test_fifo_priv/Makefile

@@ -2,7 +2,7 @@ MDEF_FILE = prj.mdef
 KERNEL_TYPE = micro
 BOARD ?= qemu_x86
 CONF_FILE = prj.conf
-SOURCE_DIR := $(ZEPHYR_BASE)/tests/kernel/test_fifo/microkernel/src
+SOURCE_DIR := $(ZEPHYR_BASE)/tests/legacy/kernel/test_fifo/microkernel/src
 # Enable testing for private microkernel FIFOs
 CFLAGS = -DTEST_PRIV_FIFO