xen: Kconfig: Fix spelling mistake "Maxmium" -> "Maximum"

There is a spelling mistake in a Kconfig description. Fix it.
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Link: https://lore.kernel.org/r/20221007203500.2756787-1-colin.i.king@gmail.comSigned-off-by: Juergen Gross <jgross@suse.com>

drivers/xen/Kconfig

@@ -56,7 +56,7 @@ config XEN_MEMORY_HOTPLUG_LIMIT
 	depends on XEN_HAVE_PVMMU
 	depends on MEMORY_HOTPLUG
 	help
-	  Maxmium amount of memory (in GiB) that a PV guest can be
+	  Maximum amount of memory (in GiB) that a PV guest can be
 	  expanded to when using memory hotplug.
 
 	  A PV guest can have more memory than this limit if is