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/trats2_defconfig b/configs/trats2_defconfig
index e8950e3..8439ddc 100644
--- a/configs/trats2_defconfig
+++ b/configs/trats2_defconfig
@@ -27,7 +27,7 @@
 CONFIG_CMD_USB_MASS_STORAGE=y
 # CONFIG_CMD_NET is not set
 CONFIG_CMD_CACHE=y
-# CONFIG_CMD_MISC is not set
+# CONFIG_CMD_SLEEP is not set
 CONFIG_CMD_EXT4_WRITE=y
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_OVERWRITE=y