configs: j721s2_evm_a72_defconfig: Switch to bootstd

Switch to using bootstd. Note that with this change, we will stop using
distro_bootcmd and instead depend entirely on bootflow method of
starting the system up.

Also config_distro_bootcmd.h header file that is no longer needed in
j721s2_evm.h.

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