misc: pci_endpoint_test: Document policy about adding pci_device_id

Add a comment suggesting that if the endpoint controller Vendor and Device
ID are programmable, an existing entry might be usable for testing without
having to add an entry to pci_endpoint_test_tbl[].

Link: https://lore.kernel.org/linux-pci/20240611125057.1232873-6-yoshihiro.shimoda.uh@renesas.comSigned-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Reviewed-by: Frank Li <Frank.Li@nxp.com>

drivers/misc/pci_endpoint_test.c

@@ -1014,6 +1014,10 @@ static const struct pci_endpoint_test_data rk3588_data = {
 	.irq_type = IRQ_TYPE_MSI,
 };
 
+/*
+ * If the controller's Vendor/Device ID are programmable, you may be able to
+ * use one of the existing entries for testing instead of adding a new one.
+ */
 static const struct pci_device_id pci_endpoint_test_tbl[] = {
 	{ PCI_DEVICE(PCI_VENDOR_ID_TI, PCI_DEVICE_ID_TI_DRA74x),
 	  .driver_data = (kernel_ulong_t)&default_data,