pbio/platform/prime_hub: Reset USB enable flag.

This should not be enabled in public builds since USB support is not yet ready, but it was accidentally enabled (and committed) while debugging in 4002d26.

Author: laurensvalk

lib/pbio/platform/prime_hub/pbdrvconfig.h

@@ -119,7 +119,7 @@
 
 #define PBDRV_CONFIG_USB                            (1)
 #define PBDRV_CONFIG_USB_MAX_PACKET_SIZE            (64)
-#define PBDRV_CONFIG_USB_NUM_BUFFERED_PACKETS       (20)
+#define PBDRV_CONFIG_USB_NUM_BUFFERED_PACKETS       (2)
 #define PBDRV_CONFIG_USB_VID                        LEGO_USB_VID
 #define PBDRV_CONFIG_USB_PID                        0xFFFF
 #define PBDRV_CONFIG_USB_PID_0                      LEGO_USB_PID_SPIKE_PRIME
@@ -128,7 +128,7 @@
 #define PBDRV_CONFIG_USB_PROD_STR                   LEGO_USB_PROD_STR_TECHNIC_LARGE_HUB " + Pybricks"
 #define PBDRV_CONFIG_USB_STM32F4                    (1)
 #define PBDRV_CONFIG_USB_STM32F4_HUB_VARIANT_ADDR   0x08007d80
-#define PBDRV_CONFIG_USB_CHARGE_ONLY                (0)
+#define PBDRV_CONFIG_USB_CHARGE_ONLY                (1)
 
 #define PBDRV_CONFIG_STACK                          (1)
 #define PBDRV_CONFIG_STACK_EMBEDDED                 (1)