greybus: Revert "arche-apb-ctrl: Remove extra delay in APB reset"

We are seeing failures on DB3.1 board, and Axel root-caused it to this
commit, so revert it as of now.

This reverts commit 942627227684c187b727ba5fb581bc2d886b6708.
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>

drivers/staging/greybus/arche-apb-ctrl.c

@@ -54,6 +54,7 @@ struct arche_apb_ctrl_drvdata {
 static inline void deassert_reset(unsigned int gpio)
 {
 	gpio_set_value(gpio, 1);
+	msleep(500);
 }
 
 static inline void assert_reset(unsigned int gpio)