Add localversion for -RT release

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

localversion-rt

diff --git a/localversion-rt b/localversion-rt
new file mode 100644
index 0000000..c3054d0
--- /dev/null
+++ b/localversion-rt
@@ -0,0 +1 @@
+-rt2