src/arch/x86/acpi: Constify struct device instances

Constify the struct device arguments in below APIs:
> acpi_device_name
> acpi_device_path_fill
> acpi_device_path
> acpi_write_dbg2_pci_uart
> acpi_device_scope
> acpi_device_path_join

The APIs do not seem to modify the argument and are using
device argument as reference to device only.

Change-Id: Ic2ce045f17efa288eb41503795723d0ad5ec78bd
Signed-off-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34625
Reviewed-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/arch/x86/acpi.c

@@ -946,7 +946,7 @@ void acpi_create_dbg2(acpi_dbg2_header_t *dbg2,
 }
 
 unsigned long acpi_write_dbg2_pci_uart(acpi_rsdp_t *rsdp, unsigned long current,
-				       struct device *dev, uint8_t access_size)
+				const struct device *dev, uint8_t access_size)
 {
 	acpi_dbg2_header_t *dbg2 = (acpi_dbg2_header_t *)current;
 	struct resource *res;