PCI: Correct pci=resource_alignment parameter example

The "pci=resource_alignment" parameter is described as requiring an order
(not a size) and the code in pci_specified_resource_alignment() expects an
order.

But the example wrongly shows a size.  Convert the example to an order.

Fixes: 8b078c60 ("PCI: Update "pci=resource_alignment" documentation")
Link: https://lore.kernel.org/r/20190606032557.107542-1-aik@ozlabs.ruSigned-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

Documentation/admin-guide/kernel-parameters.txt

@@ -3452,12 +3452,13 @@
 				specify the device is described above.
 				If <order of align> is not specified,
 				PAGE_SIZE is used as alignment.
-				PCI-PCI bridge can be specified, if resource
+				A PCI-PCI bridge can be specified if resource
 				windows need to be expanded.
 				To specify the alignment for several
 				instances of a device, the PCI vendor,
 				device, subvendor, and subdevice may be
-				specified, e.g., 4096@pci:8086:9c22:103c:198f
+				specified, e.g., 12@pci:8086:9c22:103c:198f
+				for 4096-byte alignment.
 		ecrc=		Enable/disable PCIe ECRC (transaction layer
 				end-to-end CRC checking).
 				bios: Use BIOS/firmware settings. This is the