ds2760_battery: Fix W1 and W1_SLAVE_DS2760 dependency

Fix this Kconfig warning on allmodconfig for s390:

warning: (BATTERY_DS2760 && POWER_SUPPLY) selects W1 which has unmet
direct dependencies (HAS_IOMEM)
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>

drivers/power/Kconfig

@@ -64,8 +64,7 @@ config TEST_POWER
 
 config BATTERY_DS2760
 	tristate "DS2760 battery driver (HP iPAQ & others)"
-	select W1
-	select W1_SLAVE_DS2760
+	depends on W1 && W1_SLAVE_DS2760
 	help
 	  Say Y here to enable support for batteries with ds2760 chip.