Convert CONFIG_MX_CYCLIC to Kconfig

This converts the following to Kconfig:
   CONFIG_MX_CYCLIC

Signed-off-by: Adam Ford <aford173@gmail.com>
Acked-by: David Lechner <david@lechnology.com>
diff --git a/configs/M5249EVB_defconfig b/configs/M5249EVB_defconfig
index c39818b..b93f127 100644
--- a/configs/M5249EVB_defconfig
+++ b/configs/M5249EVB_defconfig
@@ -7,6 +7,7 @@
 # CONFIG_AUTOBOOT is not set
 CONFIG_CMD_IMLS=y
 CONFIG_LOOPW=y
+CONFIG_MX_CYCLIC=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_CACHE=y
 CONFIG_DEFAULT_DEVICE_TREE="M5249EVB"