HID: Kconfig: fix syntax

Replace mistakenly used '==' by '='.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/Kconfig

@@ -33,7 +33,7 @@ config HID
 
 config HID_BATTERY_STRENGTH
 	bool
-	depends on HID && POWER_SUPPLY && HID == POWER_SUPPLY
+	depends on HID && POWER_SUPPLY && HID = POWER_SUPPLY
 	default y
 
 config HIDRAW