[DOCS] Pare down ODBC info
[DOCS] Pare down ODBC info

Remove the Cloudera-specific portion of the
Impala + ODBC page, leaving just the background
info about why to use ODBC. Defer to third parties
who supply ODBC drivers.

Change-Id: I302d23432d348aa0c9c2837c0f42bc4f2844f9b8
Reviewed-on: http://gerrit.cloudera.org:8080/6409
Reviewed-by: Jim Apple <396f577ccd0f19e47f0fb44dae1d6fc43cc20400@apache.org>
Tested-by: Impala Public Jenkins

michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,michaelhkw/incubator-impala,cloudera/Impala,cloudera/Impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,michaelhkw/incubator-impala,cloudera/Impala,cloudera/Impala