add itf argument to hid API to support multiple instances

following API signature is changed:
- tud_hid_descriptor_report_cb()
- tud_hid_get_report_cb()
- tud_hid_set_report_cb()
- tud_hid_boot_mode_cb()
- tud_hid_set_idle_cb()

src/class/hid/hid_device.h

@@ -88,8 +88,6 @@ static inline bool tud_hid_mouse_report(uint8_t report_id, uint8_t buttons, int8
 // Callbacks (Weak is optional)
 //--------------------------------------------------------------------+
 
-#if CFG_TUD_HID > 1
-
 // Invoked when received GET HID REPORT DESCRIPTOR request
 // Application return pointer to descriptor, whose contents must exist long enough for transfer to complete
 uint8_t const * tud_hid_descriptor_report_cb(uint8_t itf);
@@ -111,18 +109,6 @@ TU_ATTR_WEAK void tud_hid_boot_mode_cb(uint8_t itf, uint8_t boot_mode);
 // - Idle Rate > 0 : skip duplication, but send at least 1 report every idle rate (in unit of 4 ms).
 TU_ATTR_WEAK bool tud_hid_set_idle_cb(uint8_t itf, uint8_t idle_rate);
 
-#else
-
-// TODO for backward compatible callback, remove later when appropriate
-uint8_t const * tud_hid_descriptor_report_cb(void);
-uint16_t tud_hid_get_report_cb(uint8_t report_id, hid_report_type_t report_type, uint8_t* buffer, uint16_t reqlen);
-void tud_hid_set_report_cb(uint8_t report_id, hid_report_type_t report_type, uint8_t const* buffer, uint16_t bufsize);
-
-TU_ATTR_WEAK void tud_hid_boot_mode_cb(uint8_t boot_mode);
-TU_ATTR_WEAK bool tud_hid_set_idle_cb(uint8_t idle_rate);
-
-#endif
-
 // Invoked when sent REPORT successfully to host
 // Application can use this to send the next report
 // Note: For composite reports, report[0] is report ID