core: allow setting USB version in descriptor to USB 2 from config.h

Author: stapelberg

docs/config_options.md

@@ -105,6 +105,8 @@ This is a C header file that is one of the first things included, and will persi
   * sets the USB polling rate in milliseconds for the keyboard, mouse, and shared (NKRO/media keys) interfaces
 * `#define USB_SUSPEND_WAKEUP_DELAY 200`
   * set the number of milliseconde to pause after sending a wakeup packet
+* `#define USB_VERSION_2`
+  * set the USB device descriptor to USB version 2.
 * `#define F_SCL 100000L`
   * sets the I2C clock rate speed for keyboards using I2C. The default is `400000L`, except for keyboards using `split_common`, where the default is `100000L`.
 

tmk_core/protocol/usb_descriptor.c

@@ -351,7 +351,11 @@ const USB_Descriptor_Device_t PROGMEM DeviceDescriptor = {
         .Size                   = sizeof(USB_Descriptor_Device_t),
         .Type                   = DTYPE_Device
     },
+#if defined(USB_VERSION_2)
+    .USBSpecification           = VERSION_BCD(2, 0, 0),
+#else
     .USBSpecification           = VERSION_BCD(1, 1, 0),
+#endif
 
 #if VIRTSER_ENABLE
     .Class                      = USB_CSCP_IADDeviceClass,