xen/xenbus: Fix spelling mistake "hardward" -> "hardware"

There is a spelling mistake in the module description. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/20221004160639.154421-1-colin.i.king@gmail.com


Signed-off-by: Juergen Gross <jgross@suse.com>