[RC_V1_4_7b]Document & XRT installation instructions Fixes (#454)

* Document & XRT installation instruction updates

* Update Create_Runtime_AMI.md

Author: AWSaalluri

SDAccel/docs/Create_Runtime_AMI.md

@@ -9,9 +9,9 @@
 
 ## 1. Launch a Runtime Instance & Install Required Packages 
 
-### Using Amazon Linux
+* Please note Amazon Linux 2 or Amazon Linux are not supported by Xilinx XRT at this time. Please use Centos/RHEL or Ubuntu when using Xilinx XRT Runtimes for the AFIs generated using Xilinx SDx 2018.2 and 2018.3 toolsets.
 
-* Launch an F1 instance using an [Amazon Linux AMI](https://aws.amazon.com/marketplace/pp/B00635Y2IW)
+* Launch an F1 instance using an [Amazon Linux AMI](https://aws.amazon.com/marketplace/pp/B00635Y2IW) or [Centos 7](https://aws.amazon.com/marketplace/pp/B00O7WM7QW) 
 * Install the required updates
 
 ````

hdk/docs/SDxPatch_AR71715_and_XRT_installation_instructions.md

@@ -57,13 +57,14 @@
   
   ### Centos/RedHat Linux
   
-  Run following commands to download and install XRT 2018.2_XDF.RC4 for 'Centos/RHEL' based distributions
+  Run following commands to download and install XRT 2018.2_XDF.RC4 for 'Centos/RHEL'
   
   ```
    curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/xrt_201802.2.1.0_7.5.1804-xrt.rpm -o xrt_201802.2.1.0_7.5.1804-xrt.rpm
    curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/xrt_201802.2.1.0_7.5.1804-aws.rpm -o xrt_201802.2.1.0_7.5.1804-aws.rpm
-   sudo yum reinstall -y xrt_201802.2.1.0_7.5.1804-xrt.rpm
-   sudo yum reinstall -y xrt_201802.2.1.0_7.5.1804-aws.rpm
+   sudo yum remove -y xrt
+   sudo yum install -y xrt_201802.2.1.0_7.5.1804-xrt.rpm
+   sudo yum install -y xrt_201802.2.1.0_7.5.1804-aws.rpm
 
   ```
 
@@ -75,14 +76,16 @@
   
   ### Centos/RedHat Linux
   
-  Run following commands to download and install XRT 2018.2_XDF.RC4 for 'Centos/RHEL' based distributions
+  Run following commands to download and install XRT 2018.2_XDF.RC5 for 'Centos/RHEL'
   
   ```
    curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/XRT_2018_2_XDF_RC5/xrt_201802.2.1.0_7.5.1804-xrt.rpm -o xrt_201802.2.1.0_7.5.1804-xrt.rpm
    curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/XRT_2018_2_XDF_RC5/xrt_201802.2.1.0_7.5.1804-aws.rpm -o xrt_201802.2.1.0_7.5.1804-aws.rpm
-   sudo yum reinstall -y xrt_201802.2.1.0_7.5.1804-xrt.rpm
-   sudo yum reinstall -y xrt_201802.2.1.0_7.5.1804-aws.rpm
+   sudo yum remove -y xrt-aws
+   sudo yum remove -y xrt
+   sudo yum install -y xrt_201802.2.1.0_7.5.1804-xrt.rpm
+   sudo yum install -y xrt_201802.2.1.0_7.5.1804-aws.rpm
 
   ```
 
- 
+

sdaccel_runtime_setup.sh

@@ -69,8 +69,10 @@ function xrt_install_instructions_2018_2 {
     err_msg "use following command to download and install latest validated XRT rpms for centos distributions"
     err_msg "curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/XRT_2018_2_XDF_RC5/xrt_201802.2.1.0_7.5.1804-xrt.rpm -o xrt_201802.2.1.0_7.5.1804-xrt.rpm"
     err_msg "curl -s https://s3.amazonaws.com/aws-fpga-developer-ami/1.5.0/Patches/XRT_2018_2_XDF_RC5/xrt_201802.2.1.0_7.5.1804-aws.rpm -o xrt_201802.2.1.0_7.5.1804-aws.rpm"
-    err_msg "sudo yum reinstall -y xrt_*-xrt.rpm"
-    err_msg "sudo yum reinstall -y xrt_*-aws.rpm"
+    err_msg "sudo yum remove -y xrt-aws"
+    err_msg "sudo yum remove -y xrt"
+    err_msg "sudo yum install -y xrt_201802.2.1.0_7.5.1804-xrt.rpm"
+    err_msg "sudo yum install -y xrt_201802.2.1.0_7.5.1804-aws.rpm"
 }
 
 function check_xdma_driver {