lib: Fix mess with driver IDs

ID is just a some magic number to make fingerprint from one scanner model
incompatible with another scanner model. Get rid of "magic", declare enum
and use it.

https://bugs.freedesktop.org/show_bug.cgi?id=56956

libfprint/drivers/upekts.c

@@ -35,6 +35,8 @@
 
 #include <fp_internal.h>
 
+#include "driver_ids.h"
+
 #define EP_IN (1 | LIBUSB_ENDPOINT_IN)
 #define EP_OUT (2 | LIBUSB_ENDPOINT_OUT)
 #define TIMEOUT 5000
@@ -1464,7 +1466,7 @@ static const struct usb_id id_table[] = {
 };
 
 struct fp_driver upekts_driver = {
-	.id = 1,
+	.id = UPEKTS_ID,
 	.name = FP_COMPONENT,
 	.full_name = "UPEK TouchStrip",
 	.id_table = id_table,