cpu/nrf5x: implement pm_off() for nRF53/9160

Signed-off-by: Dylan Laduranty <dylan.laduranty@mesotic.com>

cpu/nrf5x_common/periph/pm.c

@@ -27,7 +27,11 @@
 #define NRF_POWER NRF_POWER_S
 #endif
 
-/* TODO: implement proper pm_off for nRF9160 */
+/* Workaround inconsistency between nRF9160 / nRF53 headers */
+#ifdef REGULATORS_SYSTEMOFF_SYSTEMOFF_Enable
+#define REGULATORS_SYSTEMOFF_SYSTEMOFF_Enter REGULATORS_SYSTEMOFF_SYSTEMOFF_Enable
+#endif
+
 void pm_off(void)
 {
 #if (!defined(CPU_FAM_NRF9160) && !defined(CPU_FAM_NRF53))
@@ -40,6 +44,8 @@ void pm_off(void)
     }
 #endif
     NRF_POWER->SYSTEMOFF = 1;
-    while (1) {}
+#else /* nRF9160 / nRF53 */
+    NRF_REGULATORS_S->SYSTEMOFF = REGULATORS_SYSTEMOFF_SYSTEMOFF_Enter;
 #endif /* ndef CPU_FAM_NRF9160 */
+    while (1) {}
 }