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/odroid-go2_defconfig b/configs/odroid-go2_defconfig
index d1f7a0f..8538909 100644
--- a/configs/odroid-go2_defconfig
+++ b/configs/odroid-go2_defconfig
@@ -52,7 +52,7 @@
 CONFIG_CMD_USB=y
 CONFIG_CMD_USB_MASS_STORAGE=y
 # CONFIG_CMD_ITEST is not set
-# CONFIG_CMD_MISC is not set
+# CONFIG_CMD_SLEEP is not set
 # CONFIG_SPL_DOS_PARTITION is not set
 # CONFIG_ISO_PARTITION is not set
 CONFIG_EFI_PARTITION_ENTRIES_NUMBERS=64