Handle symlink correctly on DTB source directory

On Debian trixie-backports, linux-image-6.18.9+deb13-arm64 (via
linux-image-arm64) ships /usr/lib/linux-image-6.18.9+deb13-arm64 as a
symlink to modules/6.18.9+deb13-arm64/dtb. This causes:

    cp -RT /usr/lib/linux-image-6.18.9+deb13-arm64 /boot/efi/dtb

to fail with:

    cp: cannot create symbolic link '/boot/efi/dtb': Operation not permitted

We can use -L to deference the symlink correctly.

Signed-off-by: Robie Basak <robie.basak@oss.qualcomm.com>

Author: basak-qcom

debos-recipes/qualcomm-linux-debian-image.yaml

@@ -93,7 +93,7 @@ actions:
       latest_kernel="$(
           linux-version list | linux-version sort --reverse | head -1)"
       dtb_path="/usr/lib/linux-image-${latest_kernel}"
-      cp -RT "$dtb_path" "/boot/efi/dtb"
+      cp -RTL "$dtb_path" "/boot/efi/dtb"
 
   - action: run
     description: Create task to grow root filesystem on first boot