mfd: cros: add "base attached" MKBP switch definition

This adds a "base attached" switch definition to the MKBP protocol that
is used by Whiskers driver to properly determine device state (clamshell
vs tablet mode).
Signed-off-by: Dmitry Torokhov <dtor@chromium.org>
Acked-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

include/linux/mfd/cros_ec_commands.h

@@ -2132,6 +2132,7 @@ struct ec_response_get_next_event_v1 {
 /* Switches */
 #define EC_MKBP_LID_OPEN	0
 #define EC_MKBP_TABLET_MODE	1
+#define EC_MKBP_BASE_ATTACHED	2
 
 /*****************************************************************************/
 /* Temperature sensor commands */