alpine: rename top directory

fix the image name accordingly.

Signed-off-by: Fathi Boudra <fathi.boudra@linaro.org>
Change-Id: I67f4ffe89987bc5c98dde13cc0215673d03816fe
diff --git a/alpine-amd64-node10-tf-a/build.sh b/alpine-amd64-node10-tf-a/build.sh
new file mode 100755
index 0000000..181e0b9
--- /dev/null
+++ b/alpine-amd64-node10-tf-a/build.sh
@@ -0,0 +1,10 @@
+#!/bin/sh
+
+set -e
+
+export LANG=C
+
+cp -a ../setup-sshd .
+image=trustedfirmware/ci-node-tf-a-alpine:alpine10
+docker build --pull --tag=$image .
+echo $image > .docker-tag