README: Remove likely incorrect description

Not only Poky-specific DISTRO_NAME and VERSION will
not be displayed but this string isn't even printed right
before the login prompt.

Signed-off-by: Zbigniew Bodek <zbigniew.bodek@huawei.com>

README.md

@@ -80,8 +80,6 @@ You can test the image built for the qemux86-64 target by issuing:
 
 After successful bootup, you should see following:
 
-    Poky (Yocto Project Reference Distro) 3.1.4 qemux86-64 /dev/ttyS0
-
     qemux86-64 login:
     
 Default login is _root_ without a password.