usb: pci_quirks: fix sparse 'symbol not declared' warning

This commit fixes the following sparse warning:

drivers/usb/host/pci-quirks.c:
    - 252: warning: symbol 'usb_hcd_amd_remote_wakeup_quirk' was not
      declared. Should it be static?

This function is exported so the fix was to add it's declaration to the
header file.

Signed-off-by: Konrad Zapalowicz <bergo.torino@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>