[nrf toup] tests: drivers: counter: Add clock stabilization nRF

Xtal LF clock source starts hundreds of milliseconds. When it is
not start, test may fail due to wrong timing. Added pending
on LF clock being start in test setup.

Signed-off-by: Krzysztof Chruscinski <krzysztof.chruscinski@nordicsemi.no>
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
(cherry picked from commit 94b7d5a)
(cherry-picked from commit 7cf7991)
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
(cherry picked from commit ade600a)
Signed-off-by: Martí Bolívar <marti.bolivar@nordicsemi.no>

tests/drivers/counter/counter_basic_api/src/test_counter.c

@@ -9,6 +9,10 @@
 #include <kernel.h>
 #include <logging/log.h>
 LOG_MODULE_REGISTER(test);
+#ifdef CONFIG_SOC_FAMILY_NRF
+#include <drivers/clock_control/nrf_clock_control.h>
+#include <clock_control.h>
+#endif
 
 static volatile u32_t top_cnt;
 static volatile u32_t alarm_cnt;
@@ -81,6 +85,16 @@ typedef bool (*counter_capability_func_t)(const char *dev_name);
 
 static void counter_setup_instance(const char *dev_name)
 {
+#ifdef CONFIG_SOC_FAMILY_NRF
+	struct device *clock =
+		device_get_binding(DT_INST_0_NORDIC_NRF_CLOCK_LABEL "_32K");
+
+	__ASSERT_NO_MSG(clock);
+
+	while (clock_control_on(clock, (void *)CLOCK_CONTROL_NRF_K32SRC) != 0) {
+		/* empty */
+	}
+#endif
 	alarm_cnt = 0U;
 }