doc: board: ti: Update to use the new boot firmware labels

Use the new boot_firmwares labels that help make documentation more
specific as to which firmwares are used in which devices

Signed-off-by: Dhruva Gole <d-gole@ti.com>
diff --git a/doc/board/beagle/j721e_beagleboneai64.rst b/doc/board/beagle/j721e_beagleboneai64.rst
index d6b9c8c..090b2b3 100644
--- a/doc/board/beagle/j721e_beagleboneai64.rst
+++ b/doc/board/beagle/j721e_beagleboneai64.rst
@@ -42,6 +42,10 @@
     :start-after: .. k3_rst_include_start_boot_sources
     :end-before: .. k3_rst_include_end_boot_sources
 
+.. include::  ../ti/k3.rst
+    :start-after: .. k3_rst_include_start_boot_firmwares
+    :end-before: .. k3_rst_include_end_boot_firmwares
+
 Build procedure:
 ----------------
 0. Setup the environment variables: