device: Constify struct device * parameter to write_acpi_tables

.write_acpi_tables() should not be updating the device structure. This
change makes the struct device * argument to it as const.

Change-Id: I50d013e83a404e0a0e3837ca16fa75c7eaa0e14a
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40701
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Raul Rangel <rrangel@chromium.org>
diff --git a/src/northbridge/intel/ironlake/gma.c b/src/northbridge/intel/ironlake/gma.c
index c8bbbfd..d0f6bde 100644
--- a/src/northbridge/intel/ironlake/gma.c
+++ b/src/northbridge/intel/ironlake/gma.c
@@ -211,7 +211,7 @@
 }
 
 static unsigned long
-gma_write_acpi_tables(struct device *const dev,
+gma_write_acpi_tables(const struct device *const dev,
 		      unsigned long current,
 		      struct acpi_rsdp *const rsdp)
 {