arm: mach-k3: am642: Add support for triggering ddr init from SPL

In SPL, DDR should be made available by the end of board_init_f()
so that apis in board_init_r() can use ddr. Adding support for
triggering DDR initialization from board_init_f().

Signed-off-by: Dave Gerlach <d-gerlach@ti.com>
2 files changed