hal clean up

- replace tusb_hal_int_enable/disable to dcd_int_enable/disable,
hcd_int_enable/disable
- remove tusb_hal_init(), this will be part of dcd_init/hcd_init,
anything beyond dcd/hcd should be inited by bsp

src/tusb.c

@@ -47,14 +47,11 @@
 
 static bool _initialized = false;
 
-
 tusb_error_t tusb_init(void)
 {
   // skip if already initialized
   if (_initialized) return TUSB_ERROR_NONE;
 
-  TU_VERIFY( tusb_hal_init(), TUSB_ERROR_FAILED ) ; // hardware init
-
 #if MODE_HOST_SUPPORTED
   TU_ASSERT_ERR( usbh_init() ); // host stack init
 #endif