dt-bindings: usb: xhci: Add num-hc-interrupters definition

Add the definition for how many interrupts the XHCI host controller should
allocate.  XHCI can potentially support up to 1024 interrupters, which
implementations may want to limit.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Wesley Cheng <quic_wcheng@quicinc.com>
Link: https://lore.kernel.org/r/20240102214549.22498-15-quic_wcheng@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>