device: Constify struct device * parameter to acpi_fill_ssdt()

.acpi_fill_ssdt() does not need to modify the device structure. This
change makes the struct device * parameter to acpi_fill_ssdt() as
const.

Change-Id: I110f4c67c3b6671c9ac0a82e02609902a8ee5d5c
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40710
Reviewed-by: HAOUAS Elyes <ehaouas@noos.fr>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/drivers/net/r8168.c b/src/drivers/net/r8168.c
index c547f17..b904586 100644
--- a/src/drivers/net/r8168.c
+++ b/src/drivers/net/r8168.c
@@ -306,7 +306,7 @@
 
 #if CONFIG(HAVE_ACPI_TABLES)
 #define R8168_ACPI_HID "R8168"
-static void r8168_net_fill_ssdt(struct device *dev)
+static void r8168_net_fill_ssdt(const struct device *dev)
 {
 	struct drivers_net_config *config = dev->chip_info;
 	const char *path = acpi_device_path(dev->bus->dev);