Allow larger SPLIT_USB_TIMEOUT with default SPLIT_USB_TIMEOUT_POLL (#17272)

* Switch SPLIT_USB_DETECT loop to uint16_t

* Add assertion

quantum/split_common/split_util.c

@@ -57,8 +57,9 @@ static uint8_t connection_errors = 0;
 volatile bool isLeftHand = true;
 
 #if defined(SPLIT_USB_DETECT)
+_Static_assert((SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL) <= UINT16_MAX, "Please lower SPLIT_USB_TIMEOUT and/or increase SPLIT_USB_TIMEOUT_POLL.");
 static bool usbIsActive(void) {
-    for (uint8_t i = 0; i < (SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL); i++) {
+    for (uint16_t i = 0; i < (SPLIT_USB_TIMEOUT / SPLIT_USB_TIMEOUT_POLL); i++) {
         // This will return true if a USB connection has been established
         if (usb_connected_state()) {
             return true;