update docs

Signed-off-by: Nshawn_he <shawn.he@huawei.com>

en/application-dev/reference/apis/js-apis-battery-info.md

@@ -9,6 +9,10 @@
 import batteryInfo from '@ohos.batteryInfo';
 ```
 
+## System Capabilities
+
+SystemCapability.PowerManager.BatteryManager
+
 ## Attributes<a name="section0536924123914"></a>
 
 Describes battery information.

en/application-dev/reference/apis/js-apis-power.md

@@ -9,13 +9,10 @@
 import power from '@ohos.power';
 ```
 
-## Required Permissions<a name="section11257113618419"></a>
+## System Capabilities
 
-Shutdown: ohos.permission.SHUTDOWN
+SystemCapability.PowerManager.PowerManager
 
-Reboot: ohos.permission.REBOOT
-
-Reboot and entering the recovery mode: ohos.permission.REBOOT\_RECOVERY
 
 ## power.shutdownDevice<a name="section192192415554"></a>