drm/xe: Add configfs to enable survivability mode

drm/xe: Add configfs to enable survivability mode

Registers a configfs subsystem called 'xe' that creates a
directory in the mounted configfs directory (/sys/kernel/config)
Userspace can then create the device that has to be configured
under the xe directory

	mkdir /sys/kernel/config/xe/0000:03:00.0

The device created will have the following attributes to be
configured

	/sys/kernel/config/xe/
		.. 0000:03:00.0/
			... survivability_mode

v2: fix kernel-doc
    fix return value (Lucas)

v3: fix kernel-doc (Lucas)

Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Lucas De Marchi <lucas.demarchi@intel.com>
Link: https://lore.kernel.org/r/20250407051414.1651616-2-riana.tauro@intel.com
Signed-off-by: Lucas De Marchi <lucas.demarchi@intel.com>