Platform: Implement UART uninitialize function

This patch introduces an uninitialize function for the UART
peripheral to restore it's default state before passing
execution to runtime image from MCUBoot.

Change-Id: Iaf239b575be82402b9c142e990fb0ea30ffe9a88
Signed-off-by: David Vincze <david.vincze@arm.com>
diff --git a/platform/ext/common/uart_stdout.c b/platform/ext/common/uart_stdout.c
index 75e8b18..7a41f1e 100755
--- a/platform/ext/common/uart_stdout.c
+++ b/platform/ext/common/uart_stdout.c
@@ -77,3 +77,10 @@
     ASSERT_HIGH(ret);

 }

 

+void stdio_uninit(void)

+{

+    int32_t ret = ARM_DRIVER_OK;

+    ret = TFM_DRIVER_STDIO.Uninitialize();

+    ASSERT_HIGH(ret);

+}

+