samples/static_lib: Add testcase.ini

Add testcase.ini file for qemu_x86.

We detected an unexpected behavior in sanitycheck before submitting
this patch:

  In testcase.ini, if platform_whitelist contains more than one
  platform only the last platform will work. So, here we just use
  qemu_x86.

  However, we believe this situation is caused by the structure of
  this sample. See mylib/Makefile.

Jira: ZEP-621

Change-Id: I656c1b9a69b93fd9f7b0d98a69f49b9641918a93
Signed-off-by: Flavio Santes <flavio.santes@intel.com>

samples/static_lib/Makefile

@@ -14,25 +14,29 @@
 # limitations under the License.
 #
 
+KERNEL_TYPE = nano
+BOARD ?= qemu_x86
+CONF_FILE = prj.conf
+
 MYLIB = mylib/lib/libmylib.a
 
 all:
-	make clean
-	make mylib
-	make hello_world
+	$(MAKE) clean
+	$(MAKE) mylib
+	$(MAKE) hello_world
 
 hello_world: $(MYLIB)
-	make -C hello_world
+	$(MAKE) -C hello_world
 
 $(MYLIB):
-	make -C mylib
+	$(MAKE) -C mylib
 
 run:
-	make -C hello_world qemu
+	$(MAKE) -C hello_world qemu
 
 pristine:
-	make -C mylib clean
-	make -C hello_world pristine
+	$(MAKE) -C mylib clean
+	$(MAKE) -C hello_world pristine
 
 clean:
-	make pristine
+	$(MAKE) pristine

samples/static_lib/prj.conf

@@ -0,0 +1 @@
+# nothing yet

samples/static_lib/testcase.ini

@@ -0,0 +1,4 @@
+[test]
+tags = static_link
+build_only = true
+platform_whitelist = qemu_x86