Updated USB product name to remove duplication

Output from lsusb now reads: SparkFun Electronics Thing Plus - STM32

Author: NathanY3G

ports/stm/boards/sparkfun_stm32_thing_plus/mpconfigboard.mk

@@ -1,7 +1,7 @@
 USB_VID = 0X1B4F
 USB_PID = 0x0028
 
-USB_PRODUCT = "SparkFun Thing Plus - STM32"
+USB_PRODUCT = "Thing Plus - STM32"
 USB_MANUFACTURER = "SparkFun Electronics"
 
 SPI_FLASH_FILESYSTEM = 1