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/phytec/phycore-am64x.rst b/doc/board/phytec/phycore-am64x.rst
index 68d78ad..01c42b9 100644
--- a/doc/board/phytec/phycore-am64x.rst
+++ b/doc/board/phytec/phycore-am64x.rst
@@ -30,6 +30,10 @@
     :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_sysfw
+    :end-before: .. k3_rst_include_end_boot_firmwares_sysfw
+
 Build procedure
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