stm32/boards/B_L072Z_LRWAN1: Enable USB VCP support.

ports/stm32/boards/B_L072Z_LRWAN1/mpconfigboard.h

@@ -19,6 +19,7 @@
 #define MICROPY_HW_ENABLE_INTERNAL_FLASH_STORAGE (0)
 #define MICROPY_HW_ENABLE_RTC       (1)
 #define MICROPY_HW_ENABLE_ADC       (0)
+#define MICROPY_HW_ENABLE_USB       (1)
 #define MICROPY_HW_HAS_SWITCH       (1)
 
 // UART config
@@ -58,3 +59,10 @@
 #define MICROPY_HW_LED4             (pin_B7) // Red
 #define MICROPY_HW_LED_ON(pin)      (mp_hal_pin_high(pin))
 #define MICROPY_HW_LED_OFF(pin)     (mp_hal_pin_low(pin))
+
+// USB config (need to bridge SB15/SB16)
+#define MICROPY_HW_USB_FS           (1)
+#define MICROPY_HW_USB_MSC          (0)
+#define MICROPY_HW_USB_HID          (0)
+#define USBD_CDC_RX_DATA_SIZE       (256)
+#define USBD_CDC_TX_DATA_SIZE       (256)

ports/stm32/boards/B_L072Z_LRWAN1/mpconfigboard.mk

@@ -1,5 +1,6 @@
 MCU_SERIES = l0
 CMSIS_MCU = STM32L072xx
+MICROPY_FLOAT_IMPL = none
 AF_FILE = boards/stm32l072_af.csv
 LD_FILES = boards/stm32l072xz.ld boards/common_basic.ld