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/k2g_evm_defconfig b/configs/k2g_evm_defconfig
index 48d7fdc..0188399 100644
--- a/configs/k2g_evm_defconfig
+++ b/configs/k2g_evm_defconfig
@@ -21,6 +21,7 @@
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_POWER_SUPPORT=y
 CONFIG_SPL_SPI_LOAD=y
+CONFIG_MX_CYCLIC=y
 # CONFIG_CMD_FLASH is not set
 # CONFIG_CMD_GPIO is not set
 # CONFIG_CMD_GPT is not set