cmd: Rename CMD_MISC to CMD_SLEEP

The "cmd/Kconfig" has a TODO description for CMD_MISC that it should
really be named as CMD_SLEEP. Change it in the whole source tree.

Signed-off-by: Bin Meng <bin.meng@windriver.com>
diff --git a/configs/armadillo-800eva_defconfig b/configs/armadillo-800eva_defconfig
index ab84978..e06ef7d 100644
--- a/configs/armadillo-800eva_defconfig
+++ b/configs/armadillo-800eva_defconfig
@@ -31,7 +31,7 @@
 CONFIG_CMD_DHCP=y
 CONFIG_CMD_MII=y
 CONFIG_CMD_PING=y
-# CONFIG_CMD_MISC is not set
+# CONFIG_CMD_SLEEP is not set
 CONFIG_ENV_OVERWRITE=y
 CONFIG_ENV_IS_IN_FLASH=y
 CONFIG_ENV_ADDR=0x40000