driver core: Add fw_devlink.strict kernel param

This param allows forcing all dependencies to be treated as mandatory.
This will be useful for boards in which all optional dependencies like
IOMMUs and DMAs need to be treated as mandatory dependencies.

Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Saravana Kannan <saravanak@google.com>
Link: https://lore.kernel.org/r/20210205222644.2357303-4-saravanak@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/fwnode.h

@@ -162,6 +162,7 @@ static inline void fwnode_init(struct fwnode_handle *fwnode,
 }
 
 extern u32 fw_devlink_get_flags(void);
+extern bool fw_devlink_is_strict(void);
 int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup);
 void fwnode_links_purge(struct fwnode_handle *fwnode);