drivers/net/r8168: add ACPI _STA field entry

Add _STA field entry for r8168 ACPI device and set to
ACPI_STATUS_DEVICE_HIDDEN_ON in order to hide device from
OS (Windows) as there is no driver needed (or available).
Windows correctly attaches drivers to the PCIe device, the
separate ACPI device is unused and unneeded.

Linux is unaffected as it does not use the ACPI device status.

Change-Id: Ib7ae99fffcb00e71421b93c2794119841aa239d3
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/75177
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/net/r8168.c b/src/drivers/net/r8168.c
index dcf863a..f21edd0 100644
--- a/src/drivers/net/r8168.c
+++ b/src/drivers/net/r8168.c
@@ -378,6 +378,7 @@
 
 	if (dev->chip_ops)
 		acpigen_write_name_string("_DDN", dev->chip_ops->name);
+	acpigen_write_STA(ACPI_STATUS_DEVICE_HIDDEN_ON);
 
 	/* Power Resource */
 	if (CONFIG(RT8168_GEN_ACPI_POWER_RESOURCE) && config->has_power_resource) {