cns3xxx: enable mpcore watchdog

Signed-off-by: Koen Vandeputte <[email protected]>

target/linux/cns3xxx/config-4.9

@@ -189,7 +189,7 @@ CONFIG_MMC_SDHCI_CNS3XXX=y
 CONFIG_MMC_SDHCI_PLTFM=y
 # CONFIG_MMC_TIFM_SD is not set
 CONFIG_MODULES_USE_ELF_REL=y
-# CONFIG_MPCORE_WATCHDOG is not set
+CONFIG_MPCORE_WATCHDOG=y
 CONFIG_MTD_M25P80=y
 # CONFIG_MTD_OF_PARTS is not set
 CONFIG_MTD_PHYSMAP=y