Update zephyr version files for 2.0.0-rc1

Update for the rc1 release.

Signed-off-by: David Brown <david.brown@linaro.org>
diff --git a/boot/zephyr/VERSION b/boot/zephyr/VERSION
index 465a403..c359e4c 100644
--- a/boot/zephyr/VERSION
+++ b/boot/zephyr/VERSION
@@ -1,5 +1,5 @@
-VERSION_MAJOR = 1
-VERSION_MINOR = 11
-PATCHLEVEL = 99
+VERSION_MAJOR = 2
+VERSION_MINOR = 0
+PATCHLEVEL = 0
 VERSION_TWEAK = 0
-EXTRAVERSION = dev
+EXTRAVERSION = rc1