Disable boards which does not fulfil new sleep standards.

These boards will be re-enabled when sleep driver for them is ready.

Note:
This operation is done by removing "SLEEP" feature from target's "device_has" list (in targets.json config file).
For NRF52_DK removing of "SLEEP" feature causes some timing issues which have influence on tests. In order to successfully disable this board we need to disable also related features like "USTICKER", "LOWPOERTIMER" and slightly modify ticker tests, so they will not be executed if usticker support is not available (by default all targets support us ticker).

Author: mprse

TESTS/mbed_drivers/ticker/main.cpp

@@ -18,6 +18,9 @@
 #include "utest/utest.h"
 #include "unity/unity.h"
 
+#if !DEVICE_USTICKER
+  #error [NOT_SUPPORTED] test not supported
+#endif
 
 using utest::v1::Case;
 

TESTS/mbed_drivers/timer/main.cpp

@@ -22,6 +22,10 @@
 #include "rtos.h"
 #include "hal/us_ticker_api.h"
 
+#if !DEVICE_USTICKER
+  #error [NOT_SUPPORTED] test not supported
+#endif
+
 using namespace utest::v1;
 
 extern uint32_t SystemCoreClock;