DOCS: Add change kernel version

Signed-off-by: Youngsoo Shin <sysx114@gmail.com>

Writerside/d.tree

@@ -15,6 +15,7 @@
     <toc-element toc-title="U-Boot">
     </toc-element>
     <toc-element toc-title="Odroid">
+        <toc-element topic="Change-kernel-version.md"/>
     </toc-element>
     <toc-element toc-title="About">
     </toc-element>

Writerside/topics/Change-kernel-version.md

@@ -0,0 +1,29 @@
+# Change kernel version
+
+Some features may be limited depending on the kernel version.
+Need to change the kernel version, use the method below.
+
+## Install kernel from package server
+
+Below is an example of changing to kernel version 5.9.0.
+
+```Bash
+sudo apt update
+sudo apt install linux-image-5.9.0-odroid-arm64
+sudo flash-kernel --force 5.9.0-odroid-arm64
+```
+
+
+## View installed kernel list
+Use `linux-version` command, you can see list of installed kernel list.
+```Bash
+linux-version list
+5.9.0-odroid-arm64
+5.9.15-odroid-arm64
+```
+
+## Change kernel
+Use `flask-kernel`.
+```Bash
+sudo flash-kernel --force 5.9.0-odroid-arm64
+```