sh: Fix up SH-3 and SH-4 driver dependencies.

Both shwdt and rtc-sh are only supported on SH-3 and SH-4 at
the moment, don't allow them to break the SH-2 and SH-5 (sh64)
builds.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/drivers/char/watchdog/Kconfig b/drivers/char/watchdog/Kconfig
index 2f48ba3..ad5cc5f 100644
--- a/drivers/char/watchdog/Kconfig
+++ b/drivers/char/watchdog/Kconfig
@@ -602,7 +602,7 @@
 
 config SH_WDT
 	tristate "SuperH Watchdog"
-	depends on SUPERH
+	depends on SUPERH && (CPU_SH3 || CPU_SH4)
 	help
 	  This driver adds watchdog support for the integrated watchdog in the
 	  SuperH processors. If you have one of these processors and wish