doc: Adjust README.md dependencies

  * gawk is required by package {host-}localedef
  * cpio is required by squashfs
  * xxd (vim-common on Fedora) is required by openpower-pnor
  * rsync is required by buildroot in Fedora
  * hostname is required by hcode in Fedora

Signed-off-by: Klaus Heinrich Kiwi <klaus@linux.vnet.ibm.com>
diff --git a/README.md b/README.md
index 8e8d880..45a3df3 100644
--- a/README.md
+++ b/README.md
@@ -55,7 +55,7 @@
 3. Install the packages necessary for the build:
 
         sudo apt-get install cscope ctags libz-dev libexpat-dev \
-          python language-pack-en texinfo \
+          python language-pack-en texinfo gawk cpio xxd \
           build-essential g++ git bison flex unzip \
           libssl-dev libxml-simple-perl libxml-sax-perl libxml-parser-perl libxml2-dev libxml2-utils xsltproc \
           wget bc rsync
@@ -70,5 +70,5 @@
           "perl(YAML)" "perl(XML::SAX)" "perl(Fatal)" "perl(Thread::Queue)" \
           "perl(Env)" "perl(XML::LibXML)" "perl(Digest::SHA1)" "perl(ExtUtils::MakeMaker)" \
           libxml2-devel which wget unzip tar cpio python bzip2 bc findutils ncurses-devel \
-          openssl-devel make libxslt vim-common lzo-devel python2
+          openssl-devel make libxslt vim-common lzo-devel python2 rsync hostname