[MIPS] TXx9 watchdog support for rbhma3100,rbhma4200,rbhma4500

This patch adds support for txx9wdt driver to rbhma3100, rbhma4200 and
rbhma4500 platform.

Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/configs/rbhma4500_defconfig b/arch/mips/configs/rbhma4500_defconfig
index d1b56cc..ebc8ad4 100644
--- a/arch/mips/configs/rbhma4500_defconfig
+++ b/arch/mips/configs/rbhma4500_defconfig
@@ -450,7 +450,6 @@
 CONFIG_LEGACY_PTYS=y
 CONFIG_LEGACY_PTY_COUNT=256
 # CONFIG_IPMI_HANDLER is not set
-# CONFIG_WATCHDOG is not set
 # CONFIG_HW_RANDOM is not set
 # CONFIG_RTC is not set
 # CONFIG_R3964 is not set
@@ -479,6 +478,20 @@
 # CONFIG_W1 is not set
 # CONFIG_POWER_SUPPLY is not set
 # CONFIG_HWMON is not set
+CONFIG_WATCHDOG=y
+# CONFIG_WATCHDOG_NOWAYOUT is not set
+
+#
+# Watchdog Device Drivers
+#
+# CONFIG_SOFT_WATCHDOG is not set
+CONFIG_TXX9_WDT=m
+
+#
+# PCI-based Watchdog Cards
+#
+# CONFIG_PCIPCWATCHDOG is not set
+# CONFIG_WDTPCI is not set
 
 #
 # Multifunction device drivers