am33xx: Add support for TI AM335x StarterKit EVM

- Board requires gpio0 #7 to be set to power DDR3.
- Board uses DDR3, add a way to determine which DDR type to call
  config_ddr with.
- Both of the above require filling in the header structure early, move
  it into the data section.

Signed-off-by: Tom Rini <trini@ti.com>
3 files changed