Convert CONFIG_CMD_TCA642X to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_TCA642X

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>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index d2e7c29..ffeda94 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -165,6 +165,15 @@
 	  of 'anonymous' GPIOs that do not belong to any device or bank.
 	  Select a suitable value depending on your needs.
 
+config CMD_TCA642X
+	bool "tca642x - Command to access tca642x state"
+	help
+	  DEPRECATED - This needs conversion to driver model
+
+	  This provides a way to looking at the pin state of this device.
+	  This mirrors the 'gpio' command and that should be used in preference
+	  to custom code.
+
 config TEGRA_GPIO
 	bool "Tegra20..210 GPIO driver"
 	depends on DM_GPIO