Fix swapped manufacturer/product strings

the */usb_strings.txt files always assumed that the first line is the
manufacturer string, followed by the product string in the second line.

However, the enum strDescNum had it the other way around. Let's fix it
by adjusting the enum to reality.

Fixes: SYS#3591

firmware/libcommon/source/usb.c

@@ -47,8 +47,8 @@
  *------------------------------------------------------------------------------*/
 #include "usb_strings_generated.h"
 enum strDescNum {
-	PRODUCT_STRING = 1,
+	MANUF_STR = 1,
-	MANUF_STR,
+	PRODUCT_STRING,
 	SNIFFER_CONF_STR,
 	CCID_CONF_STR,
 	PHONE_CONF_STR,