usb: xhci: avoid warning for !PM_SLEEP
usb: xhci: avoid warning for !PM_SLEEP

If we build a kernel with PM_SUSPEND set and no PM_SLEEP,
we get a build warning in the xhci-plat driver about unused
functions.

To fix this, use "#ifdef CONFIG_PM_SLEEP", like we do in most
other drivers nowadays.

Signed-off-by: Arnd Bergmann <f2c659f01951776204a6c5b902787d9019fbeebd@arndb.de>
Cc: Mathias Nyman <2d4473c5e67eb83655334d4e9a7757f781607241@intel.com>
Signed-off-by: Greg Kroah-Hartman <4645f7897fd33786a2ee1264d590b3c400559d85@linuxfoundation.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs