mips: separate extable.h, switch module.h to it

more victims of indirect include chains - au1200fb
lasat/picvue_proc and watchdog/ath79_wdt

... as well as tb0219, spotted by Sudip Mukherjee

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/drivers/watchdog/ath79_wdt.c b/drivers/watchdog/ath79_wdt.c
index 835d310..e2209bf 100644
--- a/drivers/watchdog/ath79_wdt.c
+++ b/drivers/watchdog/ath79_wdt.c
@@ -35,6 +35,7 @@
 #include <linux/err.h>
 #include <linux/of.h>
 #include <linux/of_platform.h>
+#include <linux/uaccess.h>
 
 #define DRIVER_NAME	"ath79-wdt"