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/xilinx_versal_mini_defconfig b/configs/xilinx_versal_mini_defconfig
index 3d1cba3..e72cef9 100644
--- a/configs/xilinx_versal_mini_defconfig
+++ b/configs/xilinx_versal_mini_defconfig
@@ -47,7 +47,7 @@
 # CONFIG_CMD_ITEST is not set
 # CONFIG_CMD_SOURCE is not set
 # CONFIG_CMD_SETEXPR is not set
-# CONFIG_CMD_MISC is not set
+# CONFIG_CMD_SLEEP is not set
 # CONFIG_PARTITIONS is not set
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 # CONFIG_NET is not set