scripts: Update required toolchain version to 2.2.0

Update required toolchain version for release 2.2.0.

Signed-off-by: Jamie McCrae <jamie.mccrae@nordicsemi.no>

Author: nordicjm

scripts/ncs-toolchain-version-minimum.txt

@@ -1,3 +1,3 @@
 # This file specifies the minimum nRF Connect SDK Toolchain that will be
 # working with this release.
-nrf-connect-sdk-toolchain=2.1.0
+nrf-connect-sdk-toolchain=2.2.0