hwaccess: Constify `addr` argument of MMIO read functions

Change-Id: I1419241a8332b74103b3921df2c615bdf91346a7
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/18881
Tested-by: build bot (Jenkins)
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Youness Alaoui <snifikino@gmail.com>
Reviewed-by: David Hendricks <david.hendricks@gmail.com>
2 files changed