usb: host: xhci-plat: Assign shared_hcd->rsrc_start

usb: host: xhci-plat: Assign shared_hcd->rsrc_start

When inserting a USB device, examining hcd->rsrc_start can be
helpful in identifying which hcd is mounted, as the physical
address represented here is typically unique.

The following code snippet demonstrates this:
  struct usb_hcd *hcd = bus_to_hcd(udev->bus);
  unsigned long long usb_hcd_addr = (unsigned long long)hcd->rsrc_start;

However, this approach has limitations now. For USB hosts with an
MMIO interface, the effectiveness of this method is restricted to
USB 2.0.

Because commit 3429e91a661e ("usb: host: xhci: add platform driver
support") assigned res->start to hcd->rsrc_start. But
shared_hcd->rsrc_start remains unassigned, which is also necessary
in certain scenarios.

Fixes: 3429e91a661e ("usb: host: xhci: add platform driver support")
Co-developed-by: Xu Rao <raoxu@uniontech.com>
Signed-off-by: Xu Rao <raoxu@uniontech.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Link: https://lore.kernel.org/r/186B9F56972457B4+20250107133854.172309-1-wangyuli@uniontech.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>