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/legoev3_defconfig b/configs/legoev3_defconfig
index 78cca8e..0f9f624 100644
--- a/configs/legoev3_defconfig
+++ b/configs/legoev3_defconfig
@@ -14,6 +14,7 @@
 CONFIG_AUTOBOOT_STOP_STR="l"
 CONFIG_CMD_ASKENV=y
 CONFIG_CRC32_VERIFY=y
+CONFIG_MX_CYCLIC=y
 # CONFIG_CMD_FLASH is not set
 CONFIG_CMD_MMC=y
 CONFIG_CMD_SF=y