yocto-project-qs, ref-manual, poky.ent: CentOS Package updates

Fixes [YOCTO #8696]

Turns out the 'dnf' command is not yet supported for CentOS
as it is for Fedora, I changed the 'dnf' command back to
'yum'.  Also, there were some essential packages that needed
to be added to CentOS.  Finally, there was a slight
inconsistency in the Fedora list of essential packages and the
ones for supporting Graphics.  I had a redundant listing of
one of the packages.  I took that out of the Graphics area and
left it only in the essentials area.

(From yocto-docs rev: dde72542ca87bfdd82d713f90938a41c83ac8a4d)

Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/documentation/yocto-project-qs/yocto-project-qs.xml b/documentation/yocto-project-qs/yocto-project-qs.xml
index c36cccd4d4..5315dfec6c 100644
--- a/documentation/yocto-project-qs/yocto-project-qs.xml
+++ b/documentation/yocto-project-qs/yocto-project-qs.xml
@@ -318,7 +318,7 @@
                         </para></listitem>
                     <listitem><para><emphasis>CentOS</emphasis>
                         <literallayout class='monospaced'>
-     $ sudo dnf install &CENTOS_HOST_PACKAGES_ESSENTIAL; SDL-devel xterm
+     $ sudo yum install &CENTOS_HOST_PACKAGES_ESSENTIAL; SDL-devel xterm
                         </literallayout>
                         <note>
                             CentOS 6.x users need to ensure that the required