Boot: Update MCUboot url

MCUboot URL was changed from https://github.com/JuulLabs-OSS/mcuboot
to https://github.com/mcu-tools/mcuboot

Signed-off-by: Tamas Ban <tamas.ban@arm.com>
Change-Id: If5e3d103ed420258046b7cf1071d36bf5e883476
diff --git a/docs/getting_started/tfm_secure_boot.rst b/docs/getting_started/tfm_secure_boot.rst
index 05fdb35..2a07800 100644
--- a/docs/getting_started/tfm_secure_boot.rst
+++ b/docs/getting_started/tfm_secure_boot.rst
@@ -28,7 +28,7 @@
 Second stage bootloader in TF-M
 *******************************
 By default, the MCUboot project from
-`GitHub <https://github.com/JuulLabs-OSS/mcuboot>`__ is used as the secure
+`GitHub <https://github.com/mcu-tools/mcuboot>`__ is used as the secure
 bootloader in TF-M. The repository is going to be automatically downloaded by
 CMake. The version downloaded can be controlled by the ``MCUBOOT_VERSION``
 CMake variable. If you wish to use a locally downloaded copy, the CMake variable