separate fake ehci's run async & period list

refractor list_find_previous_item & list_remove_qhd to act on ehci_link_t* instead of ehci_qhd_t*
fully support 1ms, 2ms, 4ms, 8ms for period list (each list has a dummy queue head)
- change period list structure
limit the maximum polling interval to 256 ms
add max_loop static MAX number of iteration for list_find_previous_item
add test for close 256ms polling interrupt

tinyusb/host/ehci/ehci.h

@@ -449,8 +449,8 @@ typedef struct {
 
 #if EHCI_PERIODIC_LIST
   // for NXP ECHI, only implement 1 ms & 2 ms & 4 ms, 8 ms (framelist)
-  // [0] : 1ms, [1] : 2ms, [2] : 4ms
-  ehci_qhd_t period_head_arr[CONTROLLER_HOST_NUMBER][3];
+  // [0] : 1ms, [1] : 2ms, [2] : 4ms, [3] : 8 ms
+  ehci_qhd_t period_head_arr[CONTROLLER_HOST_NUMBER][4];
 #endif
 
   //------------- Data for Address 0 (use async head as its queue head) -------------//