Convert CONFIG_CMD_TERMINAL to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_TERMINAL

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

cmd/Kconfig

@@ -1094,6 +1094,14 @@ config CMD_QFW
 
 source "cmd/mvebu/Kconfig"
 
+config CMD_TERMINAL
+	bool "terminal - provides a way to attach a serial terminal"
+	help
+	  Provides a 'cu'-like serial terminal command. This can be used to
+	  access other serial ports from the system console. The terminal
+	  is very simple with no special processing of characters. As with
+	  cu, you can press ~. (tilde followed by period) to exit.
+
 endmenu
 
 config CMD_BOOTSTAGE

include/config_cmd_all.h

@@ -13,7 +13,6 @@
  * Alphabetical list of all possible commands.
  */
 
-#define CONFIG_CMD_TERMINAL	/* built-in Serial Terminal	*/
 #define CONFIG_CMD_UNIVERSE	/* Tundra Universe Support	*/
 #define CONFIG_CMD_ZFS		/* ZFS Support			*/
 

include/configs/vct.h

@@ -239,8 +239,6 @@ int vct_gpio_get(int pin);
  * (NOR/OneNAND) usage and Linux kernel booting.
  */
 #if defined(CONFIG_VCT_SMALL_IMAGE)
-#undef CONFIG_CMD_TERMINAL
-
 #undef CONFIG_SMC911X
 #undef CONFIG_SYS_I2C_SOFT
 #undef CONFIG_SOURCE

scripts/config_whitelist.txt

@@ -293,7 +293,6 @@ CONFIG_CM922T_XA10
 CONFIG_CMDLINE_EDITING
 CONFIG_CMDLINE_PS_SUPPORT
 CONFIG_CMDLINE_TAG
-CONFIG_CMD_TERMINAL
 CONFIG_CMD_TFTP
 CONFIG_CMD_THOR_DOWNLOAD
 CONFIG_CMD_TRACE