binman: ti-secure: Enable debug extension for combined boot

To debug using jtag, ROM needs to unlock jtag debugging on HS devices
and it does that looking at this debug extension.

Add the debug extension and enable it by default.

Link: https://software-dl.ti.com/tisci/esd/latest/2_tisci_msgs/security/sec_cert_format.html?highlight=debug#sysfw-debug-ext


Signed-off-by: Manorit Chawdhry <m-chawdhry@ti.com>
Reviewed-by: Neha Malcom Francis <n-francis@ti.com>