SDK_VERSION: Use Zephyr SDK 0.17.0

This commit updates ZEPHYR_SDK to point to the Zephyr SDK 0.17.0 release.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
diff --git a/SDK_VERSION b/SDK_VERSION
index 74aaa3f..c5523bd 100644
--- a/SDK_VERSION
+++ b/SDK_VERSION
@@ -1 +1 @@
-0.16.8
+0.17.0