mei: bus: Initial MEI Client bus type implementation

mei client bus will present some of the mei clients
as devices for other standard subsystems

Implement the probe, remove, match, device addtion routines, along with
the sysfs and uevent ones. mei_cl_device_id is also added to
mod_devicetable.h
A mei-cleint-bus.txt document describing the rationale and the API usage
is also added while ABI/testing/sysfs-bus-mei describeis the modalias ABI.

Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

scripts/mod/devicetable-offsets.c

@@ -174,5 +174,8 @@ int main(void)
 	DEVID_FIELD(x86_cpu_id, model);
 	DEVID_FIELD(x86_cpu_id, vendor);
 
+	DEVID(mei_cl_device_id);
+	DEVID_FIELD(mei_cl_device_id, name);
+
 	return 0;
 }

scripts/mod/file2alias.c

@@ -1133,6 +1133,18 @@ static int do_x86cpu_entry(const char *filename, void *symval,
 }
 ADD_TO_DEVTABLE("x86cpu", x86_cpu_id, do_x86cpu_entry);
 
+/* Looks like: mei:S */
+static int do_mei_entry(const char *filename, void *symval,
+			char *alias)
+{
+	DEF_FIELD_ADDR(symval, mei_cl_device_id, name);
+
+	sprintf(alias, MEI_CL_MODULE_PREFIX "%s", *name);
+
+	return 1;
+}
+ADD_TO_DEVTABLE("mei", mei_cl_device_id, do_mei_entry);
+
 /* Does namelen bytes of name exactly match the symbol? */
 static bool sym_is(const char *name, unsigned namelen, const char *symbol)
 {