src/device: Fix discarded-qualifiers compilation issue

coreboot build is broken due to
CL: I6830a65bc9cea2907f4209bb97a53ccebcbf248d

This patch ensures to build coreboot successfully.

Change-Id: I4c9dfc9b19ce159ce1abcfbb287be4ce273cbaf1
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/25985
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
diff --git a/src/console/post.c b/src/console/post.c
index 1caa4b5..969c7c7 100644
--- a/src/console/post.c
+++ b/src/console/post.c
@@ -108,7 +108,7 @@
 	spin_unlock(&cmos_post_lock);
 }
 
-void post_log_path(struct device *dev)
+void post_log_path(const struct device *dev)
 {
 	if (dev) {
 		/* Encode path into lower 3 bytes */
diff --git a/src/device/device_util.c b/src/device/device_util.c
index 3d7f5a1..a64b63a 100644
--- a/src/device/device_util.c
+++ b/src/device/device_util.c
@@ -209,7 +209,7 @@
  * @param dev The device path to encode.
  * @return Device path encoded into lower 3 bytes of dword.
  */
-u32 dev_path_encode(struct device *dev)
+u32 dev_path_encode(const struct device *dev)
 {
 	u32 ret;
 
diff --git a/src/include/console/console.h b/src/include/console/console.h
index 1ecf89c..535401f 100644
--- a/src/include/console/console.h
+++ b/src/include/console/console.h
@@ -31,7 +31,7 @@
 #if IS_ENABLED(CONFIG_CMOS_POST_EXTRA)
 void post_log_extra(u32 value);
 struct device;
-void post_log_path(struct device *dev);
+void post_log_path(const struct device *dev);
 void post_log_clear(void);
 #else
 #define post_log_extra(x) do {} while (0)
diff --git a/src/include/device/device.h b/src/include/device/device.h
index 48a5bcc..744836d 100644
--- a/src/include/device/device.h
+++ b/src/include/device/device.h
@@ -185,7 +185,7 @@
 void assign_resources(struct bus *bus);
 const char *dev_name(struct device *dev);
 const char *dev_path(const struct device *dev);
-u32 dev_path_encode(struct device *dev);
+u32 dev_path_encode(const struct device *dev);
 const char *bus_path(struct bus *bus);
 void dev_set_enabled(struct device *dev, int enable);
 void disable_children(struct bus *bus);