[SPARK-4953][Doc] Fix the description of building Spark with YARN

At the section "Specifying the Hadoop Version" In building-spark.md, there is description about building with YARN with Hadoop 0.23.
Spark 1.3.0 will not support Hadoop 0.23 so we should fix the description.

Author: Kousuke Saruta <sarutak@oss.nttdata.co.jp>

Closes #3787 from sarutak/SPARK-4953 and squashes the following commits:

ee9c355 [Kousuke Saruta] Removed description related to a specific vendor
9ab0c24 [Kousuke Saruta] Fix the description about building SPARK with YARN

docs/building-spark.md

@@ -60,7 +60,7 @@ mvn -Dhadoop.version=2.0.0-mr1-cdh4.2.0 -DskipTests clean package
 mvn -Phadoop-0.23 -Dhadoop.version=0.23.7 -DskipTests clean package
 {% endhighlight %}
 
-For Apache Hadoop 2.x, 0.23.x, Cloudera CDH, and other Hadoop versions with YARN, you can enable the "yarn" profile and optionally set the "yarn.version" property if it is different from "hadoop.version". As of Spark 1.3, Spark only supports YARN versions 2.2.0 and later.
+You can enable the "yarn" profile and optionally set the "yarn.version" property if it is different from "hadoop.version". Spark only supports YARN versions 2.2.0 and later.
 
 Examples: