Update README.md for 2022.2 release

Signed-off-by: Peter Colberg <[email protected]>
(cherry picked from commit 951b4f7)

Author: pcolberg

README.md

@@ -42,7 +42,7 @@ Perform these steps to build the runtime:
 2.  Switch to the [latest release](https://github.com/intel/fpga-runtime-for-opencl/releases) version.
 
     ```
-    git checkout v2022.1
+    git checkout v2022.2
     ```
 
 3.  Create and change to the runtime build directory.