ieee802154: add support for channel pages from IEEE 802.15.4-2006

IEEE 802.15.4-2006 adds new concept: channel pages, which can contain several
channels. Add support for channel pages in the API and in the fakehard driver.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

include/linux/nl802154.h

@@ -64,6 +64,8 @@ enum {
 	IEEE802154_ATTR_COORD_REALIGN,
 	IEEE802154_ATTR_SEC,
 
+	IEEE802154_ATTR_PAGE,
+
 	__IEEE802154_ATTR_MAX,
 };