Add guide to validate if camera overlay is enabled

Camera overlay can be enabled by setting the correct UEFI variable.
To validate if the changes have been processed correctly, one can
check the UEFI serial logs displayed after reboot.

Author: abinjose-qualcomm

topic/k2c-qli-build-ga/enable_dtb_overlay.rst

@@ -31,6 +31,25 @@ Apply the DTB Overlay:
      sync
      reboot
 
+After rebooting, you can check the UEFI serial logs to verify that the camx overlay has
+been applied. Below is an example log snippet captured from the iq‑8275‑evk platform:
+
+.. container:: nohighlight
+
+  ::
+
+      Variable VendorDtbOverlays read successfully. Data: camx
+      ProcessQcomRuntimeOverlayRequest: Parsed camx 
+       
+      FindConfigToBoot:Booting with = qcom,qcs8275-iot-camx
+      FindConfigToBoot: i = 0 fdt fdt-monaco-evk.dtb str len = 18
+      FindConfigToBoot: i = 1 fdt fdt-monaco-evk-camx.dtbo str len = 24
+      ParseFitDt::
+      Config fdt-monaco-evk.dtb & Type 0
+      Config fdt-monaco-evk-camx.dtbo & Type 1
+      FitLoadDtbFromFdt: Config fdt-monaco-evk.dtb & Type 0
+      FitLoadDtbFromFdt: Config fdt-monaco-evk-camx.dtbo & Type 1
+
 Enable upstream video driver
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
@@ -57,4 +76,4 @@ After rebooting the device, you can run ``lsmod`` to confirm if the changes have
       lsmod | grep venus
       # Expected Output
       # venus_enc           28672   0
-      # venus_dec           28672   0
+      # venus_dec           28672   0