cmd: mdc/mwc: normalize disjoint MX_CYCLIC usage

Both CMD_MX_CYCLIC and MX_CYCLIC are in use and defined in Kconfig,
but only the non-CMD version currently does anything. This changes all
usages to prefer the CMD_MX_CYCLIC option (since it's only affecting
addition of the commands), and switches defconfigs using the non-CMD
version to use the CMD version.

Signed-off-by: Joel Johnson <mrjoel@lixil.net>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/bcm958622hr_defconfig b/configs/bcm958622hr_defconfig
index b18690a..ee6eb91 100644
--- a/configs/bcm958622hr_defconfig
+++ b/configs/bcm958622hr_defconfig
@@ -13,7 +13,7 @@
 CONFIG_CMD_BOOTZ=y
 CONFIG_CMD_ASKENV=y
 CONFIG_CRC32_VERIFY=y
-CONFIG_MX_CYCLIC=y
+CONFIG_CMD_MX_CYCLIC=y
 # CONFIG_CMD_SETEXPR is not set
 CONFIG_CMD_CACHE=y
 CONFIG_CMD_TIME=y