usb: charger: assign specific number for enum value

To work properly on every architectures and compilers, the enum value
needs to be specific numbers.

Suggested-by: Greg KH <[e-mail]>
Signed-off-by: Peter Chen <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

include/uapi/linux/usb/charger.h

···
  * ACA (Accessory Charger Adapters)
  */
 enum usb_charger_type {
-	UNKNOWN_TYPE,
-	SDP_TYPE,
-	DCP_TYPE,
-	CDP_TYPE,
-	ACA_TYPE,
+	UNKNOWN_TYPE = 0,
+	SDP_TYPE = 1,
+	DCP_TYPE = 2,
+	CDP_TYPE = 3,
+	ACA_TYPE = 4,
 };
 
 /* USB charger state */
 enum usb_charger_state {
-	USB_CHARGER_DEFAULT,
-	USB_CHARGER_PRESENT,
-	USB_CHARGER_ABSENT,
+	USB_CHARGER_DEFAULT = 0,
+	USB_CHARGER_PRESENT = 1,
+	USB_CHARGER_ABSENT = 2,
 };
 
 #endif /* _UAPI__LINUX_USB_CHARGER_H */