Change VERSION to VERSTION_STR for silab build

Author: clumsy-stefan

src/silabs/zigbee_end_device.slcp

@@ -116,7 +116,7 @@ configuration:
 - {name: EMBER_AF_PLUGIN_OTA_STORAGE_SIMPLE_EEPROM_STORAGE_START, value: '458752'}
 - {name: EMBER_AF_PLUGIN_OTA_STORAGE_SIMPLE_EEPROM_STORAGE_END, value: '753664'}
 - {name: EMBER_AF_PLUGIN_OTA_CLIENT_AUTO_START, value: '1'}
-- {name: EMBER_AF_PLUGIN_OTA_CLIENT_POLICY_FIRMWARE_VERSION, value: 'VERSION'}
+- {name: EMBER_AF_PLUGIN_OTA_CLIENT_POLICY_FIRMWARE_VERSION, value: 'VERSION_STR'}
 - {name: EMBER_AF_PLUGIN_OTA_CLIENT_POLICY_IMAGE_TYPE_ID, value: 'IMAGE_TYPE'}
 - {name: SL_IOSTREAM_USART_INST_PERIPHERAL, value: 'USART0'}
 - {name: SL_IOSTREAM_USART_INST_PERIPHERAL_NO, value: '0'}