device: acpi_name() should take a const struct device

There's no reason to mutate the struct device when determining
the ACPI name for a device. Adjust the function pointer
signature and the respective implementations to use const
struct device.

Change-Id: If5e1f4de36a53646616581b01f47c4e86822c42e
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: https://review.coreboot.org/21527
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 54d4ec3..1d2afe8 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -65,7 +65,7 @@
 		unsigned long start, struct acpi_rsdp *rsdp);
 	void (*acpi_fill_ssdt_generator)(struct device *dev);
 	void (*acpi_inject_dsdt_generator)(struct device *dev);
-	const char *(*acpi_name)(struct device *dev);
+	const char *(*acpi_name)(const struct device *dev);
 #endif
 	const struct pci_operations *ops_pci;
 	const struct i2c_bus_operations *ops_i2c_bus;