doc: Update manual for CentOS

docs/linux-setup.rst

@@ -9,6 +9,10 @@ Install some packages
 
 To compile with ESP-IDF you need to get the following packages:
 
+- CentOS 7::
+
+    sudo yum install git wget make ncurses-devel flex bison gperf python pyserial
+
 - Ubuntu and Debian::
 
     sudo apt-get install git wget make libncurses-dev flex bison gperf python python-serial
@@ -81,6 +85,10 @@ In any case, here are the steps to compile the toolchain yourself.
 
 - Install dependencies:
 
+  - CentOS 7::
+
+        sudo yum install gawk gperf grep gettext ncurses-devel python python-devel automake bison flex texinfo help2man libtool
+
   - Ubuntu pre-16.04::
 
         sudo apt-get install gawk gperf grep gettext libncurses-dev python python-dev automake bison flex texinfo help2man libtool