xhci: remove unused command member from struct xhci_hcd struct

The u32 command was added to struct xhci_hcd over 10 years ago in
commit 9777e3ce ("USB: xHCI: bus power management implementation")

It wasn't even used back then, so remove it.
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
Link: https://lore.kernel.org/r/20220921123450.671459-6-mathias.nyman@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/host/xhci.h

@@ -1827,7 +1827,6 @@ struct xhci_hcd {
 	/* Host controller watchdog timer structures */
 	unsigned int		xhc_state;
 	unsigned long		run_graceperiod;
-	u32			command;
 	struct s3_save		s3;
 /* Host controller is dying - not responding to commands. "I'm not dead yet!"
  *